U.S. patent application number 13/964368 was filed with the patent office on 2014-02-13 for lighting apparatus.
This patent application is currently assigned to SAMSUNG ELECTRONICS CO.,LTD.. The applicant listed for this patent is SAMSUNG ELECTRONICS CO.,LTD.. Invention is credited to Sok Hyun JO, Hyung Jin KIM, Wook Pyo LEE, Sang Ho YOON.
Application Number | 20140043810 13/964368 |
Document ID | / |
Family ID | 49999326 |
Filed Date | 2014-02-13 |
United States Patent
Application |
20140043810 |
Kind Code |
A1 |
JO; Sok Hyun ; et
al. |
February 13, 2014 |
LIGHTING APPARATUS
Abstract
A lighting apparatus including a base with a coupling rim and a
supporting plate and a housing coupled to the coupling rim such
that the supporting plate is covered. The housing includes a
channel part to guide air in and an air introduction hole to
introduce the guided air into an inner space of the housing. A
cooling fan is included and is disposed on an upper surface of the
supporting plate covered by the housing, wherein the cooling fan
draws air introduced through the air introduction hole into the
inner space of the housing, and discharges the in-drawn air outside
through an air discharging hole in the base. A light source module
is included and mounted on a lower surface of the supporting plate,
wherein the channel part provides a region depressed in a stepped
manner along an outer surface of the housing.
Inventors: |
JO; Sok Hyun; (Incheon,
KR) ; YOON; Sang Ho; (Yongin-si, KR) ; LEE;
Wook Pyo; (Seoul, KR) ; KIM; Hyung Jin;
(Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SAMSUNG ELECTRONICS CO.,LTD. |
Suwon-si |
|
KR |
|
|
Assignee: |
SAMSUNG ELECTRONICS
CO.,LTD.
Suwon-si
KR
|
Family ID: |
49999326 |
Appl. No.: |
13/964368 |
Filed: |
August 12, 2013 |
Current U.S.
Class: |
362/235 ;
362/249.01; 362/294; 362/373 |
Current CPC
Class: |
F21V 3/061 20180201;
H05K 1/056 20130101; H05K 3/107 20130101; F21V 29/83 20150115; F21V
29/506 20150115; H05K 2201/10106 20130101; H05K 2201/09154
20130101; F21V 13/04 20130101; H05K 1/053 20130101; F21V 29/677
20150115; H01L 2224/48091 20130101; F21S 8/026 20130101; F21V 3/062
20180201; F21V 29/74 20150115; F21Y 2115/10 20160801; H05K
2201/09845 20130101; F21V 5/10 20180201; H01L 2924/181 20130101;
F21V 5/04 20130101; F21V 29/507 20150115; H05B 47/19 20200101; H01L
2224/48091 20130101; H01L 2924/00014 20130101; H01L 2924/181
20130101; H01L 2924/00012 20130101 |
Class at
Publication: |
362/235 ;
362/373; 362/294; 362/249.01 |
International
Class: |
F21V 29/02 20060101
F21V029/02; F21V 5/04 20060101 F21V005/04; F21V 15/01 20060101
F21V015/01; F21V 29/00 20060101 F21V029/00; F21V 13/04 20060101
F21V013/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 10, 2012 |
KR |
10-2012-0087933 |
Jun 26, 2013 |
KR |
10-2013-0073701 |
Claims
1. A lighting apparatus comprising: a base comprising a coupling
rim and a supporting plate on an inner side of the coupling rim; a
housing configured to be coupled to the coupling rim such that the
supporting plate is covered, the housing comprising a channel part
that is configured to guide an introduction of air and an air
introduction hole that is configured to introduce the air guided
through the channel part into an inner space of the housing; a
cooling fan disposed on an upper surface of the supporting plate
covered by the housing, wherein the cooling fan is configured to
draw air introduced through the air introduction hole into the
inner space of the housing, and discharge the in-drawn air outside
through an air discharging hole in the base; and a light source
module mounted on a lower surface of the supporting plate, wherein
the channel part provides a region depressed in a stepped manner
along an outer surface of the housing.
2. The lighting apparatus of claim 1, wherein the air introduction
hole comprises a ring shape along a circumference of the housing
within the region depressed in the stepped manner of the channel
part, and wherein the channel part is upwardly extended along an
outer side of the housing from a lower end of the housing to
communicate with the air introduction hole.
3. The lighting apparatus of claim 1, wherein the air introduction
hole comprises a ring shape along a circumference of the housing,
and wherein the channel part comprises a first channel along the
circumference of the housing in a position corresponding to the air
introduction hole to communicate with the air introduction hole,
and a second channel extended from the first channel to the lower
end of the housing to be exposed to the outside.
4. The lighting apparatus of claim 1, wherein the channel part
comprises a plurality of channels, and wherein at least one of the
plurality of channels are recessed in the outer surface of the
housing to communicate with the air introduction hole.
5. The lighting apparatus of claim 1, wherein the coupling rim
comprises a groove having a shape and a position corresponding to
the channel part such that the coupling rim is operable to connect
with the channel part of the housing.
6. The lighting apparatus of claim 1, wherein the coupling rim
comprises: a flange part protruding outwardly from a lower end
thereof, wherein the flange part comprises a plurality of vents
formed in a circumference of the coupling rim.
7. The lighting apparatus of claim 1, wherein the base comprises an
air discharging hole between an outer circumferential surface of
the supporting plate and an inner surface of the coupling rim to
radially discharge the air introduced into the inner space of the
housing.
8. The lighting apparatus of claim 1, wherein the base comprises an
air discharging hole in a central portion of the supporting plate
to discharge the air introduced into the inner space of the
housing.
9. The lighting apparatus of claim 1, wherein the base comprises a
plurality of heat radiation fins on the upper surface of the
supporting plate facing the cooling fan.
10. A light source module comprising: a base comprising an air
discharging hole; a housing comprising: a channel part provided by
a depressed region in a stepped manner along an outer surface of
the housing; and an air introduction hole configured to introduce
air guided through the channel part into an inner space of the
housing, wherein the housing is configured to be disposed on an
upper side of the base; a cooling fan, configured to be disposed
within the housing, and configured to draw air into the inner space
of the housing, and discharge the in-drawn air outwardly through
the air discharging hole; and a light source module, configured to
be disposed on a lower side of the base, and comprising at least
one light emitting device and at least one lens disposed on the
light emitting device.
11. The light source module of claim 10, wherein the at least one
lens comprises a first surface facing the at least one light
emitting device and a second surface opposing the first surface,
wherein the at least one lens comprises: a central incident surface
configured such that light from the at least one light emitting
device is incident on the central incident surface, and a
reflective portion configured to protrude toward the at least one
light emitting device along the circumference of the central
incident surface, wherein the reflective portion is symmetrical
based on a central optical axis, wherein the central incident
surface and the reflective portion are provided in the first
surface, and wherein a refractive portion is provided in the second
surface and is configured to protrude in a direction opposite the
at least one light emitting device and is configured to be
symmetrical based on the optical axis.
12. The light source module of claim 11, wherein the reflective
portion comprises a first reflective portion and a second
reflective portion having different rotational radii with respect
to the optical axis and are concentric, wherein the first
reflective portion and the second reflective portion have different
sizes.
13. The light source module of claim 12, wherein the first
reflective portion comprises: a first side incident surface to
which light from the at least one light emitting device is made
incident; and a first reflective surface reflecting the incident
light to the second surface, wherein the second reflective portion
comprises: a second side incident surface to which light from the
at least one light emitting device is made incident; and a second
reflective surface reflecting the incident light to the second
surface.
14. The light source module of claim 11, wherein the refractive
portion is configured to be disposed immediately above the at least
one light emitting device, and wherein the refractive portion
comprises: a first refractive portion comprising a curved surface
of which the optical axis is an apex; and a second refractive
portion forming a plurality of concentric circles with respect to
the optical axis and comprising a convexo-concave structure formed
along the circumference of the first refractive portion.
15. The light source module of claim 11, wherein the reflective
portion is configured to be disposed outwardly of the refractive
portion with regard to the optical axis such that the reflective
portion surrounds the refractive portion.
16. A light source device comprising: a base comprising a coupling
rim disposed on an outer perimeter of an upper surface; a housing
wherein a lower edge of the housing is configured to connect to the
coupling rim of the base; a cooling fan configured to be disposed
within the housing on the upper surface of the base; a light source
comprising at least one light emitting device configured to be
disposed on a lower surface of the base; and a backflow prevention
part configured to be disposed within the housing on an upper
surface of the cooling fan and extending from the upper surface of
the cooling fan out to an inner surface of the housing below an
introduction hole, wherein the backflow prevention part is
configured to prevent air drawn into an inner space of the housing
through the cooling fan from flowing backward.
17. The light source device of claim 16, the housing further
comprising: a first channel formed on an outer surface of the
housing, wherein the first channel extends perpendicularly and
radially in relation to a central axis; and a second channel formed
on the outer surface of the housing, wherein the second channel
extends from a lower edge of the first channel down to a lower edge
of the housing, wherein the introduction hole disposed in the first
channel.
18. The light source device of claim 16, further comprising: a
cover, configured to be disposed on the light source, comprising at
least one lens corresponding to the at least one light emitting
device, wherein the least one lens is configured refract and
reflect light from the at least one light emitting device.
19. The light source device of claim 16, the base further
comprising: at least one heat radiation fin disposed on the upper
surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the priority from Korean Patent
Application No. 10-2012-0087933 filed in the Korean Intellectual
Property Office on Aug. 10, 2012, and Korean Patent Application No.
10-2013-0073701 filed on Jun. 26, 2013, in the Korean Intellectual
Property Office, the disclosures of which are incorporated herein
by reference in there entireties.
BACKGROUND
[0002] 1. Field
[0003] Apparatuses and methods consistent with exemplary
embodiments relate to a lighting apparatus, more particularly, to a
lighting apparatus including a base, a housing, a cooling fan, and
a lighting source.
[0004] 2. Description of the Related Art
[0005] A lighting apparatus using a light emitting diode (LED) as a
light source may transfer heat generated from the light source
through a substrate to a heat sink and emit the heat into the
surrounding atmosphere. Such a heat transfer to the surrounding
atmosphere through natural convection exhibits a significantly low
efficiency and, thus, a significantly large heat sink is mounted
thereon to cool the light source. As a method of improving such a
limitation, various methods have been considered, such as a method
of increasing contact between a light source and a substrate to
enhance thermal conduction, a method of forming a substrate with a
metallic material to enhance thermal conduction, and the like.
SUMMARY
[0006] An aspect of an exemplary embodiment provides a lighting
apparatus, that may be capable of increasing a lifespan of a light
source and improving light output by overcoming limited heat
radiation efficiency according to natural convection by
significantly increasing heat radiation efficiency.
[0007] Another aspect of an exemplary embodiment provides a
lighting apparatus having a size that falls within the American
National Standards Institute (ANSI) standard range and enhanced
heat radiation with respect to a high output.
[0008] Another aspect of an exemplary embodiment provides a
lighting apparatus having a size that falls within the range set by
the American National Standards Institute (ANSI) and enhanced heat
radiation with respect to a high output thereof.
[0009] According to an aspect of an exemplary embodiment, there is
provided a lighting apparatus including: a base including a
coupling rim and a supporting plate on an inner side of the
coupling rim; a housing configured to be coupled to the coupling
rim such that the supporting plate is covered, the housing
comprising a channel part that is configured to guide an
introduction of air and an air introduction hole that is configured
to introduce the air guided through the channel part into an inner
space of the housing; a cooling fan on an upper surface of the
supporting plate covered by the housing, wherein the cooling fan is
configured to draw air introduced through the air introduction hole
into the inner space of the housing, and discharge the in-drawn air
outside through an air discharging hole in the base; and a light
source module mounted on a lower surface of the supporting plate,
wherein the channel part provides a region depressed in a stepped
manner along an outer surface of the housing.
[0010] The air introduction hole may have a ring shape along a
circumference of the housing within the region depressed in the
stepped manner of the channel part, and wherein the channel part
may be upwardly extended along an outer side of the housing from a
lower end of the housing to communicate with the air introduction
hole.
[0011] The air introduction hole may have a ring shape along a
circumference of the housing, and the channel part may include a
first channel along the circumference of the housing in a position
corresponding to the air introduction hole to communicate with the
air introduction hole, and a second channel extended from the first
channel to the lower end of the housing to be exposed to the
outside.
[0012] The channel part may include a plurality of channels, and at
least one of the plurality of channels may be recessed in the outer
surface of the housing to communicate with the air introduction
hole.
[0013] The coupling rim may include a groove having a shape and a
position corresponding to the channel part such that the coupling
rim can connect with the channel part of the housing.
[0014] The coupling rim may include a flange part protruding
outwardly from a lower end thereof, and the flange part may have a
plurality of vents formed in a circumference of the coupling
rim.
[0015] The base may include an air discharging hole between an
outer circumferential surface of the supporting plate and an inner
surface of the coupling rim to radially discharge the air
introduced into the inner space of the housing.
[0016] The base may include an air discharging hole in a central
portion of the supporting plate to discharge the air introduced
into the inner space of the housing.
[0017] The base may include a plurality of heat radiation fins on
the upper surface of the supporting plate facing the cooling
fan.
[0018] According to another aspect of an exemplary embodiment,
there is provided a light source module including: a base having an
air discharging hole; a housing including a channel part provided
by depressed region in a stepped manner along an outer surface of
the housing, and an air introduction hole configured to introduce
air guided through the channel part into an inner space of the
housing, wherein the housing is configured to be disposed on an
upper side of the base, a cooling fan configured to be disposed
within the housing, and configured to draw air into the inner space
of the housing, and discharge the in-drawn air outwardly through
the air discharging hole; and a light source module, configured to
be disposed on a lower side of the base, and including at least one
light emitting device and at least one lens disposed on the light
emitting device.
[0019] The at least one lens may have a first surface facing the at
least one light emitting device and a second surface opposing the
first surface, the at least one lens may include a central incident
surface configured such that light from the at least one light
emitting device is incident on the central incident surface, and a
reflective portion configured to protrude toward the at least one
light emitting device along the circumference of the central
incident surface, wherein the reflective portion is symmetrical
based on a central optical axis, wherein the central incident
surface and the reflective portion are provided in the first
surface, and wherein a refractive portion is provided in the second
surface and is configured to, protrude in a direction opposite the
at least one light emitting device, and is configured to be
symmetrical based on the optical axis.
[0020] The reflective portion may include a first reflective
portion and a second reflective portion having different rotational
radii with respect to the optical axis and are concentric, wherein
the first reflective portion and the second reflective portion may
have different sizes.
[0021] The first reflective portion and the second reflective
portion may each have a side incident surface to which light from
the at least one light emitting device is made incident and a
reflective surface reflecting the incident light to the second
surface.
[0022] The refractive portion may be configured to be disposed
immediately above the at least one light emitting device, and may
have a first refractive portion having a curved surface of which
the optical axis is an apex and a second refractive portion forming
a plurality of concentric circles with respect to the optical axis
and having a convexo-concave structure formed along the
circumference of the first refractive portion.
[0023] The reflective portion may be configured to be disposed
outwardly of the refractive portion with regard to the optical axis
such that the reflective portion surrounds the refractive
portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and other aspects, features and other advantages
will be more clearly understood from the following detailed
description taken in conjunction with the accompanying drawings, in
which:
[0025] FIG. 1 is an exploded perspective view schematically
illustrating a lighting apparatus according to an exemplary
embodiment;
[0026] FIG. 2 is a cross-sectional view schematically illustrating
the lighting apparatus according to an exemplary embodiment;
[0027] FIG. 3 is a perspective view schematically illustrating a
base in the lighting apparatus of FIG. 1;
[0028] FIG. 4 is a perspective view schematically illustrating a
state in which a cooling fan is disposed on the base of FIG. 3;
[0029] FIG. 5 is a perspective view schematically illustrating a
state in which a backflow prevention part is disposed on the
cooling fan of FIG. 4;
[0030] FIG. 6 is a cross-sectional view schematically illustrating
a state in which the lighting apparatus according to an exemplary
embodiment is mounted on a ceiling;
[0031] FIG. 7 is a perspective view of FIG. 6;
[0032] FIG. 8 is an exploded perspective view schematically
illustrating a lighting apparatus according to another exemplary
embodiment;
[0033] FIG. 9 is a cross-sectional view schematically illustrating
the lighting apparatus according to another exemplary
embodiment;
[0034] FIG. 10 is a perspective view schematically illustrating a
base in the lighting apparatus of FIG. 8;
[0035] FIG. 11 is a perspective view schematically illustrating a
state in which a cooling fan is disposed on the base of FIG.
10;
[0036] FIG. 12 is a perspective view schematically illustrating a
state in which a backflow prevention part is disposed on the
cooling fan of FIG. 11;
[0037] FIG. 13 is a cross-sectional view schematically illustrating
a state in which the lighting apparatus according to another
exemplary embodiment is mounted on a ceiling;
[0038] FIG. 14 is a perspective view of FIG. 13;
[0039] FIG. 15 is an exploded perspective view schematically
illustrating a lighting apparatus according to another exemplary
embodiment;
[0040] FIG. 16 is a cross-sectional view schematically illustrating
the lighting apparatus according to another exemplary
embodiment;
[0041] FIG. 17 is a cross-sectional view schematically illustrating
a state in which the lighting apparatus according to another
exemplary embodiment is mounted on a ceiling;
[0042] FIG. 18 is a perspective view schematically illustrating a
light source module of the lighting apparatus of FIG. 15;
[0043] FIG. 19 is a perspective view schematically illustrating a
lens unit of the light source module of FIG. 18;
[0044] FIGS. 20A and 20B are cutaway perspective views
schematically illustrating a lens of the lens unit of FIG. 19;
[0045] FIG. 21 is a cross-sectional view schematically illustrating
an optical path within the light source module of FIG. 18;
[0046] FIG. 22 is a graph illustrating a light distribution curve
of a lens;
[0047] FIGS. 23A through 23C are cross-sectional views
schematically illustrating processes of fabricating a lens unit
having lenses using a mold;
[0048] FIGS. 24A and 24B are cross-sectional views schematically
illustrating a condensing lens having a general structure and a
slim lens according to one or more exemplary embodiments;
[0049] FIG. 25 is a cross-sectional view schematically illustrating
an exemplary embodiment of a substrate that may be employed in the
lighting device;
[0050] FIG. 26 is a cross-sectional view schematically illustrating
another embodiment of the substrate;
[0051] FIG. 27 is a cross-sectional view schematically illustrating
a substrate according to a modification of FIG. 26;
[0052] FIGS. 28 through 31 are cross-sectional views schematically
illustrating various exemplary embodiments of the substrate;
[0053] FIG. 32 is a cross-sectional view schematically illustrating
an example of a light emitting device (LED chip) that may be
employed in a lighting device according to various exemplary
embodiments;
[0054] FIG. 33 is a cross-sectional view schematically illustrating
another example of the light emitting device (LED chip) of FIG.
32;
[0055] FIG. 34 is a cross-sectional view schematically illustrating
another example of the light emitting device (LED chip) of FIG.
32;
[0056] FIG. 35 is a cross-sectional view illustrating an example of
an LED chip mounted on a mounting substrate, as a light emitting
device (LED chip) that may be employed in a lighting device
according to various exemplary embodiments;
[0057] FIG. 36 is an International Commission on Illumination (CIE)
1931 chromaticity diagram;
[0058] FIG. 37 is a block diagram schematically illustrating a
lighting system according to an exemplary embodiment;
[0059] FIG. 38 is a block diagram schematically illustrating a
detailed configuration of a lighting unit of the lighting system
illustrated in FIG. 37 according to an exemplary embodiment;
[0060] FIG. 39 is a flow chart illustrating a method for
controlling the lighting system illustrated in FIG. 37 according to
an exemplary embodiment;
[0061] FIG. 40 is a view schematically illustrating the use of the
lighting system illustrated in FIG. 37 according to an exemplary
embodiment;
[0062] FIG. 41 is a block diagram of a lighting system according to
another exemplary embodiment;
[0063] FIG. 42 is a view illustrating a format of a ZigBee signal
according to an exemplary embodiment.
[0064] FIG. 43 is a view illustrating a sensing signal analyzing
unit and an operation control unit according to an exemplary
embodiment;
[0065] FIG. 44 is a flow chart illustrating an operation of a
wireless lighting system according to an exemplary embodiment;
[0066] FIG. 45 is a block diagram schematically illustrating
constituent elements of a lighting system according to another
exemplary embodiment;
[0067] FIG. 46 is a flow chart illustrating a method for
controlling a lighting system according to an exemplary
embodiment;
[0068] FIG. 47 is a flow chart illustrating a method for
controlling a lighting system according to another exemplary
embodiment; and
[0069] FIG. 48 is a flow chart illustrating a method for
controlling a lighting system according to another exemplary
embodiment.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0070] The following detailed description is provided to assist the
reader in gaining a comprehensive understanding of the methods,
apparatuses, and/or systems described herein. Accordingly, various
changes, modifications, and equivalents of the methods,
apparatuses, and/or systems described herein will be suggested to
those of ordinary skill in the art. The progression of processing
steps and/or operations described is an example; however, the
sequence of and/or operations is not limited to that set forth
herein and may be changed as is known in the art, with the
exception of steps and/or operations necessarily occurring in a
particular order. In addition, respective descriptions of
well-known functions and constructions may be omitted for increased
clarity and conciseness.
[0071] Exemplary embodiments will now be described in detail with
reference to the accompanying drawings. Hereinafter, exemplary
embodiments will be described in detail with reference to the
accompanying drawings. Exemplary embodiments may, however, be
embodied in many different forms and should not be construed as
being limited to exemplary embodiments set forth herein. Rather,
these exemplary embodiments are provided so that this disclosure
will be thorough and complete and will convey the scope to those
skilled in the art. In the drawings, the shapes and dimensions of
elements may be exaggerated for clarity, and the same reference
numerals will be used throughout to designate the same or like
elements.
[0072] Although the terms used herein are generic terms which are
currently widely used and are selected by taking into consideration
functions thereof, the meanings of the terms may vary according to
the intentions of persons skilled in the art, legal precedents, or
the emergence of new technologies. Furthermore, some specific terms
may be randomly selected by the applicant, in which case the
meanings of the terms may be specifically defined in the
description of the exemplary embodiment. Thus, the terms should be
defined not by simple appellations thereof but based on the
meanings thereof and the context of the description of the
exemplary embodiment. As used herein, expressions such as "at least
one of," when preceding a list of elements, modify the entire list
of elements and do not modify the individual elements of the
list.
[0073] It will be understood that when the terms "includes,"
"comprises," "including," and/or "comprising," when used in this
specification, specify the presence of stated elements and/or
components, but do not preclude the presence or addition of one or
more elements and/or components thereof. As used herein, the term
"module" refers to a unit that can perform at least one function or
operation and may be implemented utilizing any form of hardware,
software, or a combination thereof.
[0074] A lighting apparatus according to an exemplary embodiment
will be described with reference to FIGS. 1 and 2.
[0075] FIG. 1 is an exploded perspective view schematically
illustrating a lighting apparatus according to an exemplary
embodiment, and FIG. 2 is a cross-sectional view schematically
illustrating the lighting apparatus according to an exemplary
embodiment.
[0076] Referring to FIGS. 1 and 2, a lighting apparatus 10
according to an exemplary embodiment may include a base 100, a
housing 200, a cooling fan 300, and a light source module 400.
[0077] The base 100, a frame member having the cooling fan 300, and
the light source module 400 mounted thereon to be fixed thereto,
may be coupled by a coupling rim 110 and a supporting plate 120
provided on an inner side of the coupling rim 110.
[0078] The coupling rim 110 has a ring shape perpendicular to a
central axis (O), and may include a flange part 111 protruding
outwardly from a lower end thereof. As illustrated in FIGS. 6 and
7, when the lighting apparatus 10 is mounted on a structure, for
example, a ceiling 1, the flange part 111 may be inserted into a
hole 2 provided in the ceiling 1, thereby serving to fix the
lighting apparatus 10 to the ceiling 1.
[0079] The coupling rim 110 may be provided with a groove 112
depressed toward a central portion thereof. The groove 112 may have
a shape corresponding to a channel part 220 of the housing 200, to
be described below, and may be disposed in a position corresponding
to the channel part 220 of the housing 200. By doing so, the
channel part 220 may be connected to the groove 112 to be exposed
to the outside through a lower portion of the coupling rim 110.
[0080] Terms used in the specification such as `upper portion`,
`lower portion`, upper surface`, `lower surface`, and the like, are
provided based on the drawings, and in practice, the terms can be
varied according to a disposition direction of a lighting
apparatus.
[0081] The base 100 employed in the present exemplary embodiment
may be described in detail with reference to FIG. 3. As shown in
FIG. 3, the supporting plate 120 may be provided on an inner
circumferential surface of the coupling rim 110 in a horizontal
direction, perpendicular to the central axis (O) direction, and may
be partially connected to the coupling rim 110. The supporting
plate 120 may have one flat surface (an upper surface) 120a and the
other surface (a lower surface) 120b opposing each other, and a
plurality of heat radiation fins 121 may be provided on the one
surface 120a. The plurality of heat radiation fins 121 are radially
arranged in a direction from a center of the supporting plate 120
toward an edge thereof. In this case, the plurality of heat
radiation fins 121 respectively have curved surfaces and may be
arranged in a helical shape overall. The exemplary embodiment of
FIG. 3 illustrates that the plurality of heat radiation fins 121
having curved surfaces are arranged in a helical shape. However, it
is understood that one or more other exemplary embodiments are not
limited thereto, and the heat radiation fins 121 may have various
shapes, for example, a linear shape.
[0082] The one surface 120a may have a fixing part 122 protruding
therefrom to a predetermined height. The fixing part 122 may be
provided with a screw hole, such that the housing 200 and the
cooling fan 300, to be described below, may be fixed by a fixing
mechanism such as a screw s.
[0083] The light source module 400, to be described below, may be
mounted on the other surface 120b of the supporting plate 120. The
other surface 120b may have a side wall 123 along an edge thereof
and protruding downwardly to a predetermined depth. A space having
a predetermined size is provided within an inner side of the side
wall 123 to accommodate the light source module 400 therein.
[0084] The base 100 may include an air discharging hole 130 having
a slit shape between an outer circumferential surface of the
supporting plate 120 and an inner surface of the coupling rim 110.
The air discharging hole 130 may serve as a passage allowing air to
pass there through in a direction from the one surface 120a to the
other surface 120b, such that air is not stagnant in a side of the
one surface 120a, and maintain a continuous flow thereof.
[0085] The base 100 may be a part directly contacting the light
source module 400 provided as a heat source, and thus may include a
material having excellent thermal conductivity in order to perform
a heat radiation function like a heat sink. For example, the base
100 in which the coupling rim 110 and the supporting plate 120 are
integrally formed may be formed by injection molding using a metal
or resin having excellent thermal conductivity, or the like. In
addition, the coupling rim 110 and the supporting plate 120 may be
individually manufactured as individual components and then
assembled. In this case, the supporting plate 120 may be formed of
a metal or resin having excellent thermal conductivity, while the
coupling rim 110, a part grasped directly by a user during a
working operation such as lighting apparatus replacement, may be
formed of a material having relatively low thermal conductivity to
prevent burn damage.
[0086] As in FIG. 1 and FIG. 2, the housing 200 may be coupled to
one side of the base 100, in particular, to the coupling rim 110 to
cover the supporting plate 120. The housing 200 has an upwardly
convex parabolic shape and may include a terminal part 210 on an
upper end thereof so as to be connected with an external power
source (e.g., a socket) and an opening formed in a lower end
thereof coupled to the base 100. In particular, the housing 200
includes the channel part 220 forming a region depressed in a
stepped manner with respect to an outer surface of the housing 200
in order to guide introduction of air from the outside and an air
introduction hole 230 introducing the air guided through the
channel part 220 into an inner space of the housing 200.
[0087] The air introduction hole 230 may be adjacent to the upper
end of the housing 200 and formed to have a ring shape along the
circumference of the housing 200. The channel part 220 may include
a plurality of channels, and the channel part 220 may be provided
in such a manner that at least one channel is recessed in the outer
surface of the housing 200 and upwardly extended along an outer
side of the housing 200 from the lower end of the housing 200 to
communicate with the air introduction hole 230.
[0088] Specifically, the channel part 220 may include a first
channel 221 along the circumference of the housing 200 in a
position corresponding to the air introduction hole 230, to
communicate with the air introduction hole 230, and second channels
222 extended from the first channel 221 to the lower end of the
housing 200 to be exposed to the outside. The second channels 222
may be continuously connected to the groove 112 of the coupling rim
110 coupled to the lower end of the housing 200 and may be extended
to the lower portion of the coupling rim 110 to be exposed to the
outside. Thus, the air introduced from the outside may be guided
from the lower portion of the coupling rim 110 to the upper portion
of the coupling rim 110 along a portion of the outer surface of the
housing 200, that is, the channel part 220, and may be then
introduced into the inner space of the housing 200 through the air
introduction hole 230. The present exemplary embodiment provides
that the second channel 222 may be provided in pairs, the pair of
channels 222 facing each other. However, it is understood that one
or more other exemplary embodiments are not limited thereto, and
the number of the second channels 222 and locations thereof may be
variously modified.
[0089] FIG. 4 schematically illustrates a disposed state of the
cooling fan 300 on the base 100. As illustrated in FIG. 4, the
cooling fan 300 may be provided in the housing 200. The cooling fan
300 may be disposed on one surface 120a of the supporting plate 120
and may forcibly draw the air (introduced from the outside) into
the inner space of the housing 200 and discharge the in-drawn air
to the outside through the air discharging hole 130. Through such
forcible air flow, heat generated from the light source module 400
mounted on the base 100 may be promptly emitted to the outside,
lowering a temperature of the lighting apparatus 10.
[0090] The cooling fan 300 may be disposed on the fixing part 122
of the supporting plate 120 to be supportably fixed thereto. The
cooling fan 300 (specifically, an upper surface of the cooling fan
300) may be positioned to be coplanar with the air introduction
hole 230 of the housing 200 or may be disposed in a position lower
than the air introduction hole 230. By doing so, the air drawn into
the inner space of the housing 200 through the air introduction
hole 230 may pass through the cooling fan 300 and move to the base
100 to allow for a simplified air movement path, whereby the air
flow may be smoothly performed to improve heat radiation
efficiency.
[0091] FIG. 5 schematically illustrates a disposition of a backflow
prevention part 500 on the cooling fan 300. As illustrated in FIG.
5, the backflow prevention part 500 may be disposed on the cooling
fan 300 and prevent the air drawn into the inner space of the
housing 200 through the cooling fan 300 from flowing backward. The
backflow prevention part 500 may include a ring shaped body 510
having a central hole 511 and a plurality of guide pins 520
extended to the central hole 511. The present exemplary embodiment
provides that the plurality of guide pins 520 are bent to have
curved surfaces and are arranged in a helical shape. However, it is
understood that one or more other exemplary embodiments are not
limited thereto.
[0092] The ring shaped body 510 may be provided such that an outer
surface thereof contacts the inner surface of the housing 200,
whereby a gap between the cooling fan 300 and the housing 200 can
be blocked. The central hole 511 may have a shape corresponding to
that of the cooling fan 300. The ring shaped body 510 may be
positioned at least coplanarly with the air introduction hole 230
of the housing 200 or may be disposed in a position lower than the
air introduction hole 230. In this case, the cooling fan 300 may be
disposed in a position lower than the backflow prevention part 500.
Thus, the air drawn into the inner space of the housing 200 through
the air introduction hole 230 may flow to the cooling fan 300
through the central hole 511 of the ring shaped body 510.
[0093] Meanwhile, as in FIGS. 1 and 2, the light source module 400
may be mounted on the other surface 120b opposing the first surface
120a of the supporting plate 120 on which the plurality of heat
radiation fins 121 are provided, and irradiate light. The light
source module 400 may include a substrate 410, and at least one
light emitting device 420 mounted on the substrate 410.
[0094] The substrate 410 may be a general FR4 type printed circuit
board (PCB), and may include an organic resin material containing
epoxy, triazine, silicon, a polyimide, or the like, and other
organic resin materials. Alternatively, the substrate 410 may
include a ceramic material such as AlN, Al2O3, or the like, or a
metal and metal compound material, and may be a metal-core printed
circuit board (MCPCB).
[0095] The light emitting device 420 may be mounted on the
substrate 410 and may be electrically connected thereto. The light
emitting device 420, a semiconductor device generating a
predetermined wavelength of light due to external power, may
include a light emitting diode (LED). The light emitting device 420
may emit blue light, green light, or red light according to a
material contained therein, and may emit white light.
[0096] The light emitting device 420 may be provided in plural and
the plurality of light emitting devices 420 may be arranged on the
substrate 410. In this case, the plurality of light emitting
devices 420 may be variously configured, such as being the same
type of device that generates the same wavelength of light or
different types of devices that generate different wavelengths of
light. The light emitting device 420 may be LED chip, or may be a
single package including LED chip therein.
[0097] Meanwhile, a cover 600 covering the substrate 410 and the
light emitting devices 420 may be mounted on the base 100. The
cover 600 may include a transparent or translucent material, for
example, a resin such as silicon, epoxy, or the like, in order to
outwardly irradiate light generated from the light source module
400, and may also include glass.
[0098] The cover 600 may include lenses 610 to correspond to the
respective light emitting devices 420. The lenses 610 may be
disposed to face the respective light emitting devices 420 and
control an orientation angle of light generated from the light
emitting devices 420. The present exemplary embodiment provides
that the cover 600 has the lenses 610 provided thereon to
correspond to the respective light emitting devices 420. However,
it is understood that one or more exemplary embodiments are not
limited thereto. The cover 600 may protrude in a convex lens shape
such that the cover 600 may serve as a lens itself.
[0099] The cover 600 may contain a light diffusing agent. The light
diffusing agent may have a nanometer-level particle size and
include at least one material selected from among SiO2, TiO2,
Al2O3, and the like.
[0100] FIGS. 6 and 7 schematically illustrate a manner in which the
lighting apparatus 10 according to the present exemplary embodiment
is installed on a ceiling 1. A fixing unit 3 may be installed on
the ceiling 1 and may couple and fix the lighting apparatus 10 to
the ceiling 1. The fixing unit 3 may supply power to the lighting
apparatus 10. The lighting apparatus 10 may be fixed to an upper
portion of the ceiling 1 in a hermetic state by the fixing unit
3.
[0101] As illustrated in FIG. 6 and FIG. 7, the lighting apparatus
10 may be coupled to the ceiling 1 in such a manner that the
coupling rim 110 is inserted into the hole 2 of the ceiling 1. The
hole 2 of the ceiling 1 may be provided to correspond to the
coupling rim 110 and accordingly, a gap may not be generated
between the coupling rim 110 and the hole 2, other than a space
corresponding to the groove 112 of the coupling rim 110. The
present exemplary embodiment illustrates that the lighting
apparatus 10 is inserted into the hole 2 of the ceiling 1. However,
it is understood that one or more other exemplary embodiments are
not limited thereto. That is, the fixing unit 3 may be inserted and
mounted in the hole 2 of the ceiling 1, and the lighting apparatus
10 may be inserted and coupled to the fixing unit 3 through the
coupling rim 110. Even in this case, other than a space
corresponding to the groove 112 of the coupling rim 110, a gap may
not be generated between the coupling rim 110 and the groove
112.
[0102] When the cooling fan 300 disposed in the housing 200 is
operated through power supplied thereto, air A is introduced from
the outside through the groove 112, a space provided between the
coupling rim 110 and the ceiling 1, and the introduced air A may be
guided along the channel part 220 in the outer surface of the
housing 200 in a direction from the lower end of the housing 200 to
the upper end thereof. In addition, the air A may be drawn into the
inner space of the housing 200 through the air introduction hole
230 of the housing 200. The air A drawn into the inner space of the
housing 200 may be transferred to the supporting plate 120 of the
base 100 through the cooling fan 300, radially dispersed to the
edge of the supporting plate 120 along the heat radiation fins 121
provided on the supporting plate 120, and discharged to the outside
through the air discharging hole 130. In this case, heated air A'
on the supporting plate 120 may be forcibly drawn into the housing
200 and discharged to the outside together with the flow of the air
A discharged to the outside, whereby the supporting plate 120 and
the light source module 400 mounted on the supporting plate 120 may
be cooled. In addition, the interior of the housing 200 may be
cooled due to the air A continuously drawn into the housing 200 and
having low temperature. In particular, the lighting apparatus 10
according to the present exemplary embodiment may include the
channel part 220 in the outer surface of the housing 200 in order
to allow for the flow of the air A. Thus, even in the case in which
the lighting apparatus 10 is installed within the hermetic fixing
unit 3 covering the housing 200 (for example, a socket structure
having a shape corresponding to that of the housing and closely
attached to the outer surface of the housing), the air A introduced
from the outside may be drawn into the housing 200 through a space
formed due to the channel part 220. As described above, the air A
introduced from the outside and having low temperature may be
forcibly drawn to cool the lighting apparatus 10, whereby heat
radiation efficiency may be significantly increased to improve
light emitting efficiency and enhance the life span of the light
source module 400.
[0103] With reference to FIGS. 8 and 9, a lighting apparatus
according to another exemplary embodiment will be described.
[0104] FIG. 8 is an exploded perspective view schematically
illustrating a lighting apparatus according to another exemplary
embodiment, and FIG. 9 is a cross-sectional view schematically
illustrating a lighting apparatus according to another exemplary
embodiment.
[0105] Components configuring a lighting apparatus according to
another exemplary embodiment illustrated in FIGS. 8 and 9 are
substantially identical or similar to those of the exemplary
embodiment illustrated in FIG. 1 through FIG. 7 in terms of basic
structures thereof. However, because the base and the light source
module according to another exemplary embodiment have different
structures from those according to the exemplary embodiment
illustrated in FIG. 1 through FIG. 7, a description of components
overlapping with those of the aforementioned exemplary embodiment
will be omitted and configurations of the base and the light source
module will be mainly described.
[0106] Referring to FIGS. 8 and 9, a lighting apparatus 10'
according to another exemplary embodiment may include a base 100',
a housing 200', a cooling fan 300', and a light source module
400'.
[0107] The base 100' may include the coupling rim 110' and the
supporting plate 120' provided on the inner side of the coupling
rim 110'.
[0108] The coupling rim 110' has a ring shape disposed to be
parallel to a central axis (O), and may include the flange part
111' protruding outwardly from the lower end thereof. As
illustrated in FIGS. 13 and 14, when the lighting apparatus 10' is
mounted on a structure, for example, the ceiling 1, the flange part
111' may be inserted into the hole 2 formed in the ceiling 1,
thereby serving to fix the lighting apparatus 10' to the ceiling
1.
[0109] The flange part 111' may have a plurality of vents 113' in
the circumference of the coupling rim 110'. The plurality of vents
113' may be connected to the channel part 220' of the housing 200',
such that the air A may pass through the vents 113' and move to the
channel part 220'.
[0110] The base 100' employed in the present exemplary embodiment
will hereinafter be described in detail with reference to FIG. 10.
As illustrated in FIG. 10, the supporting plate 120' may be
provided on the inner circumferential surface of the coupling rim
110' such that it is perpendicular to the central axis (O), and the
entirety of an outer circumferential surface thereof may be
connected to the coupling rim 110'.
[0111] The supporting plate 120' may have the one surface (the
upper surface) 120a' and the other surface (the lower surface)
120b' opposing each other, and the plurality of heat radiation fins
121' may be provided on the first surface 120a'. The plurality of
heat radiation fins 121' are radially arranged in a direction from
the center of the supporting plate 120' toward the edge thereof. In
this case, the plurality of heat radiation fins 121' respectively
have curved surfaces and may be arranged in a helical shape
overall. The present exemplary embodiment provides that the
plurality of heat radiation fins 121' having curved surfaces are
arranged in a helical shape. However, it is understood that one or
more other exemplary embodiments are not limited thereto, and the
heat radiation fins 121' may have various shapes, for example, a
linear shape.
[0112] The one surface 120a' may have the fixing part 122'
protruding therefrom to a predetermined height. The fixing part
122' may be provided with a screw hole, such that the housing 200'
and the cooling fan 300' may be fixed by a fixing mechanism such as
the screw, s.
[0113] The light source module 400' may be mounted on the other
surface 120b' of the supporting plate 120'. The other surface 120b'
may be provided with the side wall 123' along the edge thereof and
protruding downwardly to a predetermined depth. The space having a
predetermined size is provided within the inner side of the side
wall 123' to accommodate the light source module 400' therein.
[0114] The base 100' may include the air discharging hole 130' in
the central portion of the supporting plate 120'. The air
discharging hole 130' may serve as a passage allowing the air A' to
pass there through in a direction from the one surface 120a' to the
other surface 120b', such that air A is not stagnant in the side of
the one surface 120a' and maintain a continuous flow thereof.
[0115] FIG. 11 schematically illustrates a state in which the
cooling fan 300' is disposed on the base 100'. As illustrated in
FIG. 11, the cooling fan 300' is disposed on the one surface 120a'
of the supporting plate 120'. The cooling fan 300' may be fixed to
the fixing part 122'.
[0116] As illustrated in FIG. 12, a backflow prevention part 500'
may be disposed in an upper portion of the cooling fan 300'.
[0117] The housing 200' may be coupled to the coupling rim 110' of
the base 100' to cover the supporting plate 120'. The housing 200'
has an upwardly convex parabolic shape and may include the terminal
part 210' on the upper end thereof so as to be connected with a
socket and an opening in the lower end thereof coupled to the base
100'. The housing 200' includes the channel part 220' forming a
region depressed in a stepped manner with respect to the outer
surface of the housing 200' in order to guide introduction of the
air A from the outside and the air introduction hole 230' allowing
the air A guided through the channel part 220' to be introduced
into the inner space of the housing 200'.
[0118] The air introduction hole 230' may be adjacent to the upper
end of the housing 200' and may have a ring shape along the
circumference of the housing 200'. The channel part 220' may
include a plurality of channels, and the channel part 220' may be
provided in such a manner that at least one channel is recessed in
the outer surface of the housing 200' to communicate with the air
introduction hole 230', and upwardly extended along the outer side
of the housing 200 from the lower end of the housing 200' to
communicate with the air introduction hole 230'.
[0119] The channel part 220' may be continuously connected to the
vents 113' of the coupling rim 110' coupled to the lower end of the
housing 200' and may be exposed to the outside through the vents
113'. Thus, the air A introduced from the outside may pass through
the vents 113' from the lower portion of the coupling rim 110' to
be guided to the upper portion of the coupling rim 110' along a
portion of the outer surface of the housing 200', that is, the
channel part 220', and may be then introduced into the inner space
of the housing 200' through the air introduction hole 230'. The
exemplary embodiment illustrated in FIG. 8 is different from the
exemplary embodiment of FIG. 1 in that the channel part 220' of
FIG. 8 may occupy the greater part of the surface area of the
housing 200'. The present exemplary embodiment illustrates that the
channel part 220' may include pairs of channels facing each other,
but the number of the channels of the channel part 220' and
formation location thereof may be variously modified.
[0120] The light source module 400' may be mounted on the other
surface 120b' opposing the one surface 120a' of the supporting
plate 120' on which the plurality of heat radiation fins 121' are
provided, and irradiate light. The light source module 400' may
include the substrate 410' and at least one light emitting device
420' mounted on the substrate 410'.
[0121] The substrate 410' may be a general FR4 type printed circuit
board (PCB), and may include an organic resin material containing
epoxy, triazine, silicon, polyimide, or the like, and other organic
resin materials. Alternatively, the substrate 410' may include a
ceramic material such as AlN, Al2O3, or the like, or a metal and
metal compound material, and may be a metal-core printed circuit
board (MCPCB).
[0122] The substrate 410' may include a through hole 430' in a
position thereof corresponding to the air discharging hole 130' of
the supporting plate 120'. The light emitting devices 420' may be
arranged along the circumference of the through hole 430'.
[0123] The light emitting device 420' may be mounted on the
substrate 410'. The light emitting device 420', a semiconductor
device generating a predetermined wavelength of light due to
external power applied thereto, may include a light emitting diode
(LED). The light emitting device 420' may emit blue light, green
light, or red light according to a material contained therein, and
may emit white light.
[0124] The light emitting device 420' may be provided in plural and
the plurality of light emitting devices 420' may be arranged on the
substrate 410'. In this case, the plurality of light emitting
devices 420' may be variously configured, such as being the same
type of device that generates the same wavelength of light or
different types of devices that generate different wavelengths of
light. The light emitting devices 420' may be LED chips, or may be
a single package including LED chips therein.
[0125] Meanwhile, the cover 600' covering the substrate 410' and
the light emitting devices 420' may be mounted on the base 100'.
The cover 600' may include a transparent or translucent material,
for example, a resin such as silicon, epoxy, or the like, in order
to outwardly irradiate light generated from the light source module
400', and may also include glass.
[0126] The cover 600' may include a discharging pipe 620' in a
central portion thereof, the discharging pipe 620' being connected
to the through hole 430' of the substrate 410'. Thus, the air A'
present within the housing 200' may pass through the air
discharging hole 130' of the supporting plate 120' and the through
hole 430' of the substrate 410' to be discharged to the outside
through the discharging pipe 620'.
[0127] FIGS. 13 and 14 schematically illustrate a state in which
the lighting apparatus 10' according to the present exemplary
embodiment is mounted on the ceiling 1. As illustrated, the
lighting apparatus 10' may be coupled to the ceiling 1 in such a
manner that the coupling rim 110' is inserted into a hole 2 of the
ceiling 1. The hole 2 of the ceiling 1 may be provided to
correspond to the coupling rim 110' and accordingly, a gap may not
be generated between the coupling rim 110' and the hole 2.
[0128] When the cooling fan 300' disposed in the housing 200' is
operated through power supplied thereto, ambient air A is
introduced through a plurality of vents 113' provided in the flange
part 111' and guided along the channel part 220' in the outer
surface of the housing 200' in a direction from the lower end of
the housing 200' to the upper end thereof. In addition, the air A
may be drawn into the inner space of the housing 200' through the
air introduction hole 230' of the housing 200'. The air A drawn
into the inner space of the housing 200' may be transferred to the
supporting plate 120' of the base 100' through the cooling fan
300', may pass through the air discharging hole 130' of the
supporting plate 120' and the through hole 430' of the substrate
410', and may be discharged to the outside through the discharging
pipe 620'. In this case, heated air A' on the supporting plate 120'
may be forcibly drawn into the housing 200' and discharged to the
outside together with the flow of the air discharged to the
outside, thereby cooling the supporting plate 120' and the light
source module 400' mounted on the supporting plate 120'.
[0129] Although the lighting apparatus 10' according to an
exemplary embodiment is inserted and fixed such that no gap is
generated between the hole 2 of the ceiling 1 and the coupling rim
110', ambient air A can be drawn through the vent 113' provided in
the flange part 111', and even when the lighting apparatus 10' is
fastened to an airtight fixing unit 3 like a socket structure,
ambient air A may be forcibly introduced through a space formed by
the channel part 220' provided in the surface of the housing 200'
to cool the lighting apparatus 10'.
[0130] A lighting apparatus according to another exemplary
embodiment will be described with reference to FIGS. 15 through
21.
[0131] Components constituting the lighting apparatus according to
the exemplary embodiment illustrated in FIG. 15 through FIG. 21 are
substantially identical or similar to those of the exemplary
embodiment illustrated in FIG. 1 through FIG. 7 in terms of the
basic structures thereof, except for the structure of a light
source. Thus, a description of the same components as those of the
foregoing exemplary embodiment will be omitted and a configuration
of a light source module will be largely described.
[0132] As illustrated in FIGS. 15 and 16, a lighting apparatus 10''
according to the present exemplary embodiment may include a base
100'', a housing 200'', a cooling fan 300'', and a light source
module 400''.
[0133] The base 100'' may include a coupling rim 110'' and a
supporting plate 120'' provided in an inner side of the coupling
rim 110'', and may further include an air discharging hole 130''
formed as a slit between an outer circumferential surface of the
supporting plate 120'' and an inner surface of the coupling rim
110''.
[0134] The housing 200'' may be disposed on one side of the base
100'', and coupled to the coupling rim 110'' to cover the support
plate 120''. The housing 200'' includes a channel part 200''
forming a region depressed in a stepped manner with respect to an
outer surface of the housing 200'' in order to guide the
introduction of air and an air introduction hole 230'' introducing
the air guided through the channel part 220'' to an inner space of
the housing 200''.
[0135] The cooling fan 300'' provided within the housing 200''
forcibly draws air into the inner space of the housing 200'' and
discharges the in-drawn air to the outside through the air
discharging hole 130'' provided in the base 100''.
[0136] The base 100'', the housing 200'', and the cooling fan 300''
are the same as constituent members and structure of the lighting
apparatus 10 according to the exemplary embodiment of FIG. 1, so a
detailed description thereof will be omitted.
[0137] Meanwhile, a spacer 700'' may be provided on the cooling fan
300'' in order to stop a gap between the cooling fan 300'' and the
housing 200''. The spacer 700'' may have an annular shape with a
central hole 710'' formed therein, and an outer circumferential
surface thereof is in contact with an inner surface of the housing
200''. The central hole 710'' may have a size and shape
corresponding to the cooling fan 300''. Thus, air drawn into the
interior through the air introduction hole 230'' of the housing
200'' wholly flows to the cooling fan 300'' through the central
hole 710''.
[0138] As illustrated in FIGS. 15 and 16, a power supply unit (PSU)
800'' may be accommodated in a terminal part 210'' of the housing
200'' to supply external power to the light source module 400''.
The power supply unit 800'' may include a driving circuit 810''
including a capacitor, or the like, and an electrode pin 820''
connected to the driving circuit 810'' and protruded outwardly from
the terminal part 210''. The electrode pin 820'' may be fixed
through a pin holder 830''.
[0139] The power supply unit 800'' may be disposed in a position
higher than the air introduction hole 230'' of the housing 200'',
and thus, air drawn into the inner space of the housing 200''
through the air introduction hole 230'' immediately flows to the
base 100'' through the cooling fan 300''. In this case, heat
generated by the power supply unit 800'' may be outwardly radiated
by the drawing air A.
[0140] The light source module 400'' is installed in the supporting
plate 120'' and emits light through power applied through the power
supply unit 800''. The light source module 400'' according to the
present exemplary embodiment may include at least one light
emitting device 420'' and a lens unit 440'' disposed on the light
emitting device 420'' and having a lens 450''. The light source
module 400'' may further include a substrate 410'' on which the
light emitting device 420'' is mounted.
[0141] The lens unit 440'' may be disposed on the other side of the
base 100'' to cover the substrate 410'' and the plurality of light
emitting devices 420''. The lens unit 440'' may protect the light
emitting device 420'' from an ambient environment, or in order to
improve light extraction efficiency of light emitted outwardly from
the light emitting device 420'', the lens unit 440'' may be made of
a light-transmissive material. For example, the light-transmissive
material may include polycarbonate (PC), polymethylmethacrylate
(PMMA), acryl, and the like. Also, the lens unit 440'' may be made
of a glass material, according to one or more exemplary
embodiments.
[0142] FIG. 18 schematically illustrates the light source module
400'', and FIG. 19 schematically illustrates the lens unit 440'' of
the light source module 400''.
[0143] As illustrated in FIGS. 18 and 19, the lens unit 440'' may
have a first surface 440''-1 facing the light emitting device 420''
and a second surface 440''-2 opposing the first surface 440''-1.
The lens unit 440'' may include a plurality of lenses 450''
disposed to oppose the light emitting devices 420'', respectively.
The plurality of lenses 450'' may be disposed on the light emitting
devices 420'', respectively, to adjust regions in which light
generated by the light emitting devices 420'' is irradiated
outwardly. The plurality of lenses 450'' may be integrally
connected to form the lens unit 440''.
[0144] The lens 450'' employed in the present exemplary embodiment
will be described in more detail with reference to FIGS. 20 and 21.
As illustrated in FIGS. 20 and 21, the lens 450'' may be provided
on the first surface 440''-1 and have a central incident surface
451'' to which light from the light emitting device 420'' is made
incident and a reflective portion 452'' protruding toward the light
emitting device 420'' along the circumference of the central
incident surface 451'' and being symmetrical with regard to a
central optical axis Z. The lens 450'' may have a refractive
portion 455'' provided on the second surface 440''-2 and protruded
in the opposite direction of the light emitting device 420'' and
being symmetrical with regard to the optical axis Z.
[0145] The central incident surface 451'' may be disposed
immediately above the light emitting device 420'' such that it is
perpendicular with respect to the optical axis Z passing through
the center, and may have a flat planar shape or a gentle curved
shape overall. The central incident surface 451'' may have a
depressed portion 456'' having a step structure. The depressed
portion 456'' may have a shape corresponding to an ejection pin as
described hereinafter and come into contact with the ejection
pin.
[0146] The reflective portion 452'' may have an annular shape along
the circumference of the edge of the central incident surface 451''
such that it encircles the central incident surface 451'' and may
have a first reflective portion 452a'' and a second reflective
portion 452b'' which are concentric and have different rotational
radii with respect to the optical axis Z. For example, the first
reflective portion 452a'' is provided along the circumference of
the edge of the central incident surface 451'' to cover the central
incident surface 451'', and the second reflective portion 452b''
may be provided along the circumference of the edge of the first
reflective portion 452a'' to cover the first reflective portion
452a''. The first and second reflective portions 452a'' and 452b''
may have annular shapes having different diameters with respect to
the optical axis Z.
[0147] The first reflective portion 452a'' and the second
reflective portion 452b'' may have a side incident surface 453'' to
which light from the light emitting device 420'' is incident and a
reflective surface 454'' which reflects the incident light to the
second surface 440''-2, respectively.
[0148] The side incident surface 453'' may receive light irradiated
in a lateral direction, which is included in light from the light
emitting device 420'', and to this end, the side incident surface
453'' may protrude from the first surface 440''-1 toward the light
emitting device 420'' to extend along the optical axis Z by a
predetermined distance.
[0149] The reflective surface 454'' reflects light received through
the side incident surface 453'' toward the second surface 440''-2,
and to this end, the reflective surface 454'' may have a paraboloid
shape connecting an extending end of the side incident surface
453'' and the first surface 440''-1.
[0150] In the present exemplary embodiment, it is illustrated that
the reflective surface 454'' has a paraboloid shape, but all
exemplary embodiments are not limited thereto. For example, the
reflective surface 454'' may have a linear sloped shape and may be
freely modified to have a shape as long as it can reflect light
received through the side incident surface 453'' toward the second
surface 440''-2.
[0151] Meanwhile, the reflective portion 452'' may have a structure
in which a length thereof protruded from the first surface 440''-1
is increased in a direction away from the optical axis Z. Namely,
the second reflective portion 452b'' is protruded by a greater
amount than the first reflective portion 452a'' toward the light
emitting device 420'', and thus, the second reflective portion
452b'' may be greater in size than the first reflective portion
452a'' overall.
[0152] In the present embodiment, the reflective portion 452'' has
a dual-ring structure including the first and second reflective
portions 452a'' and 452b'', but all exemplary embodiments are not
limited thereto. For example, the reflective portion 452'' may
further include a third reflective portion (not shown) having a
size and a diameter greater than those of the second reflective
portion 452b'', having a triple ring structure or more.
[0153] The second surface 440''-2 opposing the first surface
440''-1 is a light output surface emitting light, incident to the
first surface 440''-1, to the outside. The second surface 440''-2
includes the refractive portion 455'' protruded in a direction
opposite the light emitting device 420'' and being symmetrical with
regard to the optical axis Z.
[0154] The refractive portion 455'' may include a first refractive
portion 455a'' and a second refractive portion 455b'' surrounding
the first refractive portion 455a''.
[0155] The first refractive portion 455a'' may be disposed
immediately above the light emitting device 420'', and may have a
convexly curved surface using the optical axis Z as an apex. The
second refractive portion 455b'' forms a plurality of concentric
circles with respect to the optical axis Z and may have a
convexo-concave structure formed along the circumference of the
first refractive portion 455a''. The convexo-concave form of the
second refractive portion 455b'' may include a Fresnel pattern, for
example.
[0156] The refractive portion 455'' may be formed by performing an
intaglio process the flat second surface 440''-2. Namely, the
curved surface of the first refractive portion 455a'' and the
convexo-concave shape of the second refractive portion 455b'' may
be coplanar with at least the second surface 440''-2 or may be
lower than the second surface 440''-2. Thus, the refractive portion
455'' may not be protruded from the second surface 440''-2 and a
height (or thickness) TL of the lens 450'' may be defined as a
distance between an end of the reflective portion 452'' protruded
from the first surface 440''-1 and the second surface 440''-2.
[0157] In the present exemplary embodiment, the case in which the
refractive portion 455'' is not protruded from the second surface
440''-2 is illustrated, but all exemplary embodiments are not
limited thereto. For example, the refractive portion 455'' may be
partially protruded upwardly from the second surface 440''-2.
However, a degree of protrusion thereof is merely a portion with
respect to the overall height (or thickness) TL of the lens 450'',
so it does not affect the height TL of the lens 450''.
[0158] Meanwhile, the lens 450'' may have a structure in which the
reflective portion 452'' is disposed outwardly of the refractive
portion 455'' with regard to the optical axis Z to surround the
refractive portion 455''. In detail, the central incident surface
451'', opposing the refractive portion 455'' formed on the second
surface 440''-2, is formed to have a size corresponding to the
refractive portion 455'', and accordingly, the reflective portion
452'' may be disposed outwardly of the refractive portion 455'' to
surround the refractive portion 455''.
[0159] FIG. 22 is a graph showing a light distribution curve of the
lens 450''. As illustrated, it can be seen that a beam spread angle
of concentrated light ranges from about 24.degree. to 25.degree..
This means that it does not have any significant difference in
concentration capability, in comparison to the related art
condensing lens having a beam spread angle of about
24.4.degree..
[0160] The lens 450'' may be integrally formed with the lens unit
440'' by injecting a fluidic solvent into a mold and solidifying
it. For example, it may include a scheme such as injection molding,
transfer molding, compression molding, and the like.
[0161] FIGS. 23A through 23C schematically illustrate a process of
fabricating the lens unit having the lens using a mold. FIGS. 23A
through 23C are cross-sectional views schematically illustrating a
sequential process of fabricating the lens unit according to the
present exemplary embodiment.
[0162] First, as illustrated in FIG. 23A, molds M1 and M2 having a
lens shape are prepared, and a fluidic solvent, e.g., a resin, is
injected into the molds M1 and M2 and cured to complete the lens
unit 440'' having the lens 450''.
[0163] Next, as illustrated in FIG. 23B, the molds M1 and M2 are
separated to allow the completed lens unit 440'' to be partially
separated from the molds M1 and M2.
[0164] Then, as illustrated in FIG. 23C, the lens unit 440'' is
completely separated from the molds M1 and M2 through ejection pins
P provided in the molds M1 and M2. At least three or more ejection
pins P may be provided, whereby deformation of the lens unit 440''
in the course of separating the lens unit 440'' can be minimized.
For example, the ejection pins P may be configured to be in contact
with the both edge regions of the lens 450'' and a central region
of the lens 450'', such that force applied to the lens 450'' is
evenly distributed. In this case, the ejection pin P disposed to be
in contact with the central region of the lens 450'' may be in
contact with the depressed portion 456'' formed in the central
incident surface 451'' of the lens 450''.
[0165] Namely, in case of the related art condensing lens, because
it has a thickness to a degree (e.g., approximately 10 mm), the
ejection pin may be disposed outwardly of the lens in the event of
ejection molding. However, in the case in which the lens 450'' has
a small thickness (i.e., height) as in the present exemplary
embodiment, the lens 450'' may be deformed. Thus, the ejection pin
P is disposed even in the central portion to allow force applied to
the lens 450'' to be uniformly distributed to prevent deformation
of the lens unit 440''.
[0166] The lens 450'' according to the present exemplary embodiment
fabricated thusly may have a thickness (or height) ranging from
about 2 mm to 4.5 mm as illustrated in FIG. 20. Namely, the lens
450'' according to the present exemplary embodiment may have a
thickness equal to about half that of the existing condensing lens
(having a thickness equal to about 10 mm, please see FIG. 24A),
implementing a small size suitable for compactness, and when the
lens 450'' according to the present exemplary embodiment is
employed in a lighting apparatus, it may have a size that falls
within the range set by the American National Standards Institute
(ANSI) (ANSI C78.24-2001).
[0167] For example, the lamp standard (ANSI C78.24-2001) stipulated
by the ANSI requests that a light lamp having the structure
illustrated in FIG. 16 should follow standard of T1: 46 mm, T2: 4.5
mm, TT: 50.5 mm at the maximum.
[0168] In a high output lamp, such as a current 50 W MR 16 product,
which has difficulty in implementing sufficient cooling with
natural heat radiation (or dissipation) scheme, the use of a
cooling fan is essential. In this case, a size of a product due to
the installation of a cooling fan is increased to exceed the ANSI
standard.
[0169] In case of a housing limited to the dimension of T1, it has
a standardized structure for its fastening to a socket, and the
like. Thus, in the present exemplary embodiment, a lens limited the
dimension of T2 is reduced in thickness to avoid exceeding the ANSI
standard. FIGS. 24A and 24B show the comparison between a general
condensing lens and the slim-type lens according to the present
exemplary embodiment. As can be seen from the drawings, the light
lamp having a height (or thickness) reduced by about half, while
maintaining the same optical characteristics, in compliance with
the ANSI standard, can be implemented.
[0170] Meanwhile, the substrate 410'' corresponds to a base member
constituting a circuit board on which the light emitting device
420'' as an electronic device is to be mounted, and it may be a
so-called a printed circuit board (PCB). Also, the substrate 410''
may be a package body supporting the light emitting device 420'',
as a base member.
[0171] The substrate 410'' may be made of, for example, a material
such as FR-4, CEM-3, or the like, but all exemplary embodiments are
not limited thereto. For example, the substrate 410'' may also be
made of glass or an epoxy material, a ceramic material, or the
like. Also, the substrate 410'' may be made of a metal or a metal
compound or may include a metal core printed circuit board (MCPCB),
a metal copper clad laminate (MCCL), or the like.
[0172] FIG. 17 schematically illustrates a state in which the
lighting device 10'' according to the present exemplary embodiment
is installed on the ceiling 1. The fixing unit 3 may be installed
on the ceiling 1 to fasten or fix the lighting apparatus 10'', and
power may be supplied to the lighting apparatus 10''. The lighting
apparatus 10'' may be fixed to an upper portion of the ceiling 1 by
the fixing unit 3 in an airtight state.
[0173] As illustrated, the lighting apparatus 10'' may fastened to
the ceiling 1 such that the coupling rim 110'' is inserted into the
hole 2 of the ceiling 1. The hole 2 of the ceiling 1 may be
provided to correspond to the coupling rim 110'', and accordingly,
a gap may not be generated between the coupling rim 110'' and the
hole 2, other than a space corresponding to the groove 112'' of the
coupling rim 110''.
[0174] When the cooling fan 300'' disposed in the housing 200'' is
operated through power supplied thereto, air A is introduced from
the outside through the groove 112'', a space provided between the
coupling rim 110'' and the ceiling 1, and the introduced air A may
be guided along the channel part 220'' in the outer surface of the
housing 200'' in a direction from the lower end of the housing
200'' to the upper end thereof. In addition, the air A may be drawn
into the inner space of the housing 200'' through the air
introduction hole 230'' of the housing 200''. The air A drawn into
the inner space of the housing 200'' may flow to the supporting
plate 120'' of the base 100'' through the spacer 700'' and the
cooling fan 300'', radially dispersed to the edge of the supporting
plate 120'' along the heat radiation fins 121'' provided on the
supporting plate 120'', and discharged to the outside through the
air discharging hole 130''. In this case, heated air A' on the
supporting plate 120'' may be forcibly drawn into the housing 200''
and discharged to the outside together with the flow of the air A
discharged to the outside, whereby the supporting plate 120'' and
the light source module 400'' mounted on the supporting plate 120''
may be cooled. In addition, the interior of the housing 200'' may
be cooled due to the air A continuously drawn into the housing 20
and having a relatively low temperature. In particular, the
lighting apparatus 10'' according to the present exemplary
embodiment may include the channel part 220'' in the outer surface
of the housing 200'' in order to allow for the flow of the air A.
Thus, even in the case in which the lighting apparatus 10'' is
installed within the airtight fixing unit 3 covering the housing
200'' (for example, a socket structure having a shape corresponding
to that of the housing and closely attached to the outer surface of
the housing), the air A introduced from the outside may be drawn
into the housing 200'' through a space formed due to the channel
part 220''. As described above, the air A introduced from the
outside and having a relatively low temperature may be forcibly
drawn in to cool the lighting apparatus 10'', maximizing heat
radiation efficiency, and thus, the life span of the light source
module 400'' can be lengthened and luminous efficiency can be
enhanced.
[0175] Hereinafter, various substrate structures employable in
light source modules according to various exemplary embodiments as
described above will be described.
[0176] As illustrated in FIG. 25, a board 1100 may include an
insulating substrate 1110 having predetermined circuit patterns
1111 and 1112 formed on one surface thereof, an upper heat
diffusion plate 1140 formed on the insulating substrate 1110 such
that it is in contact with the circuit patterns 1111 and 1112 and
dissipating heat generated by the light emitting device 420, and a
lower heat diffusion plate 1160 formed on the other surface of the
insulating substrate 1110 and outwardly diffusing heat transmitted
by the upper heat diffusion plate 1140. The upper heat diffusion
plate 1140 and the lower heat diffusion plate 1160 may be connected
by at least one through hole 1150 penetrating the insulating
substrate 1110 and having a plated inner wall.
[0177] The circuit pattern 1111 and 1112 of the insulating
substrate 1110 may be formed by coating copper foil on a ceramic or
epoxy resin-based FR4 core and performing an etching process
thereon. An insulating thin film 1130 may be coated on a lower
surface of the board 1100.
[0178] FIG. 26 illustrates another example of the board. As
illustrated in FIG. 26, a board 1200 may include an insulating
layer 1220 formed on a first metal layer 1210 and a second metal
layer 1230 formed on the insulating layer 1220. The substrate 1200
may have a step portion `R` formed in at least one end portion
thereof and allowing the insulating layer 1220 to be exposed.
[0179] The first metal layer 1210 may be made of a material having
excellent exothermic characteristics. For example, the first metal
layer 1210 may be made of a metal such as aluminum (Al), iron (Fe),
or the like, or an alloy, and may be formed as a single layer or as
a multilayer structure. The insulating layer 1220 may be made of a
material having insulating characteristics, and may be formed of an
inorganic or organic material. For example, the insulating layer
1220 may be made of an epoxy-based insulating resin, and in order
to enhance thermal conductivity, the insulating layer 1220 may
include a metal powder such as aluminum (Al) powder, or the like,
so as to be used. The second metal layer 1230 may generally be
formed as a copper (Cu) thin film.
[0180] As illustrated in FIG. 26, in the metal board, a distance,
i.e., an insulation distance, of the exposed region of one end
portion of the insulating layer 1220 may be greater than a
thickness of the insulating layer 1220. In the present disclosure,
the insulation distance refers to a distance of the exposed region
of the insulating layer 1220 between the first metal layer 1210 and
the second metal layer 1230. When the metal board is viewed from
above, a width of the exposed region of the insulating layer 1220
is referred to as an exposure width W1. The region `R` in FIG. 26
is a region removed through a grinding process, or the like, during
a process of fabricating the metal board. An end portion of the
metal board may have a depth `h` corresponding to a distance from a
surface of the second metal layer 1230 to the insulating layer 1220
where the insulating layer 1220 is exposed by the exposure width
W1, forming a step structure. If the end portion of the metal board
is not removed, an insulation distance corresponds to a thickness
(h1+h2) of the insulating layer 1220, and by removing a portion of
the end portion, the insulation distance approximately
corresponding to a distance W1 may further be secured. Accordingly,
in the case of conducting a withstand voltage experiment with
respect to the metal board, the metal board having a structure in
which contact possibility between the two metal layers 1210 and
1230 in the end portions thereof is minimized can be provided.
[0181] FIG. 27 schematically illustrates a structure of a metal
board according to a modification of FIG. 26. Referring to FIG. 27,
a metal board 1200' includes an insulating layer 1220' formed on a
first metal layer 1210' and a second metal layer 1230' formed on
the insulating layer 1220'. The insulating layer 1220' and the
second metal layer 1230' include regions removed at a predetermined
slope angle .delta.1, and even the first metal layer 1210' may
include a region removed at the predetermined slope angle
.delta.1.
[0182] Here, the slope angle .delta.1 may be an angle between an
interface between the insulating layer 1220' and the second metal
layer 1230' and an end portion of the insulating layer 1220', and
may be selected to secure an insulation distance I in consideration
of a thickness of the insulating layer 1220'. The slope angle
.delta.1 may be selected within a range of 0<.delta.1<90
(degrees). As the slope angle .delta.1 is increased, the insulation
distance I and a width W2 of the exposed region of the insulating
layer 1220' are increased. Thus, in order to secure a greater
insulation distance, the slope angle .delta.1 may be selected to be
small. For example, the slope angle .delta.1 may be selected to be
within a range of 0<.delta.1.ltoreq.45 (degrees).
[0183] FIG. 28 schematically illustrates another example of a
board. Referring to FIG. 28, a board 1300 is formed by laminating a
resin coated copper (RCC) film 1320, which includes an insulating
layer 1321 and a copper foil 1322 laminated on the insulating layer
1321, on a metal support substrate 1310, and a portion of the RCC
film 1320 may be removed to form at least one recess allowing the
light emitting device 420 to be installed therein. In the metal
board, because the RCC film 1320 is removed from a lower region of
the light emitting device 420, the light emitting device 420 is in
direct contact with the metal support substrate 1310, whereby heat
generated by the light emitting device 420 is directly transmitted
to the metal support substrate 1310, enhancing a heat radiation (or
dissipation) performance thereof. The light emitting device 420 may
be electrically connected or fixed through soldering (solders 1340
and 1341). A protective layer 1330 made of liquefied PSR may be
formed on the copper foil 1322.
[0184] FIG. 29 schematically illustrates another example of a
board. In this embodiment, the board includes an anodized metal
board having excellent heat dissipation characteristics and
incurring low manufacturing costs. Referring to FIG. 29, the
anodized metal board 1400 may include a metal plate 1410, an
anodized oxide film 1420 formed on the metal plate 1410, and
electrical wirings 1430 formed on the anodized oxide film 1420.
[0185] The metal plate 1410 may be made of aluminum (Al) or an
aluminum alloy that may be easily obtained at relatively low cost.
Besides, the metal plate 1410 may be made of any other anodisable
metal, for example, titanium, magnesium, or the like.
[0186] The aluminum anodized oxide film (Al2O3) 1420 obtained by
anodizing aluminum has relatively high heat transmission
characteristics ranging from approximately 10 to 30 W/mK. Thus, the
anodized metal board has superior heat dissipation characteristics,
relative to a printed circuit board (PCB), a metal core printed
circuit board (MCPCB), or the like, of a conventional polymer
board.
[0187] FIG. 30 schematically illustrates another example of a
board. As illustrated in FIG. 30, a board 1500 may include an
insulating resin 1520 coated on a metal substrate 1510 and a
circuit pattern 1530 formed on the insulating resin 1520. Here, the
insulating resin 1520 may have a thickness equal to or less than
200 .mu.m. The insulating resin 1520 may be laminated as a solid
film on the metal substrate 1510 or may be coated as a liquid
according to a casting method using spin coating or a blade. Also,
the circuit pattern 1530 may be formed by filling a design of a
circuit pattern intagliated on the insulating resin 1520 with metal
such as copper (Cu), or the like. The light emitting device 420 may
be installed to be connected to the circuit pattern 1530.
[0188] Meanwhile, the board may include a flexible printed circuit
board (FPCB) that is freely deformable. As illustrated in FIG. 31,
a board 1600 may include an FPCB 1610 having one or more through
holes 1611 and a support substrate 1620 on which the FPCB 1610 is
mounted. A heat dissipation adhesive 1640 coupling a lower surface
of the light emitting device 420 and an upper surface of the
support substrate 1620 may be provided in the through hole 1611.
Here, the lower surface of the light emitting device 420 may be a
lower surface of a chip package, a lower surface of a lead frame
with a chip mounted thereon, or a metal block. The FPCB 1610
includes a circuit wiring 1630, so it can be electrically connected
to the light emitting device 420 thereby.
[0189] In this manner, by using the FPCB 1610, a thickness and a
weight can be reduced, and manufacturing costs can be reduced.
Also, because the light emitting device 420 is directly bonded to
the support substrate 1620 by the heat dissipation adhesive 1640,
enhancing heat dissipation efficiency, heat generated by the light
emitting device 420 can be easily radiated.
[0190] The foregoing board may be formed to have a flat plate
shape. However, a size and a structure of the board may be
variously modified according to a structure of an apparatus in
which the light source module according to the present exemplary
embodiment, e.g., a lighting apparatus, is to be used.
[0191] A light emitting device may be mounted on the board and
electrically connected thereto. Any photoelectric device may be
used as the light emitting device 420 as long as it can generate
light having a predetermined wavelength by power applied thereto
from the outside, and typically, the light emitting device 420 may
include a semiconductor light emitting diode (LED) in which a
semiconductor layer is epitaxially grown on a growth substrate. The
light emitting device 420 may emit blue, green, or red light
according to a material contained therein, and may also emit white
light.
[0192] For example, the light emitting device 420 may have a
laminate structure including an n-type semiconductor layer and a
p-type semiconductor layer and an active layer disposed there
between. Also, here, the active layer may be formed of a nitride
semiconductor including InxAlyGal-x-yN(0.ltoreq.x.ltoreq.1,
0.ltoreq.y.ltoreq.1, 0.ltoreq.x+y.ltoreq.1) having a single or
multi-quantum well structure.
[0193] Meanwhile, the light emitting device employable in the
lighting apparatus according to the forgoing embodiment may use LED
chips having various structures or various types of LED packages
including such LED chips. Hereinafter, various LED chips and LED
packages employable in the lighting apparatuses according to
exemplary embodiment will be described
Light Emitting Device
First Example
[0194] FIG. 32 is a side sectional view schematically illustrating
an example of a light emitting device as a light emitting diode
(LED) chip.
[0195] As illustrated in FIG. 32, a light emitting device 2000 may
include a light emitting laminate L formed on a substrate 2001. The
light emitting laminate L may include a first conductivity-type
semiconductor layer 2004, an active layer 2005, and a second
conductivity-type semiconductor layer 2006.
[0196] Also, an ohmic-contact layer 2008 may be formed on the
second conductivity-type semiconductor layer 2006, and first and
second electrodes 2009a and 2009b may be formed on upper surfaces
of the first conductivity-type semiconductor layer 2004 and the
ohmic-contact layer 2008, respectively.
[0197] In the present disclosure, terms such as `upper portion`,
`upper surface`, `lower portion`, `lower surface`, `lateral
surface`, and the like, are determined based on the drawings, and
in actuality, the terms may be changed according to a direction in
which a light emitting device is disposed.
[0198] Hereinafter, major components of a light emitting device
will be described in detail.
[0199] [Substrate]
[0200] A substrate constituting a light emitting device is a growth
substrate for epitaxial growth. As the substrate 2001, an
insulating substrate, a conductive substrate, or a semiconductor
substrate may be used. For example, the substrate 2001 may be made
of sapphire, SiC, Si, MgAl2O4, MgO, LiAlO2, LiGaO2, GaN, or the
like. In order to epitaxially grow a GaN material, a GaN substrate
as a homogeneous substrate may be used, but a GaN substrate may
incur high manufacturing costs due to difficulties in manufacturing
thereof.
[0201] As a heterogeneous substrate, a sapphire substrate, a
silicon carbide substrate, or the like, is commonly used, and in
this case, a sapphire substrate is more frequently utilized,
relative to a relatively expensive silicon carbide substrate. In
the case of using a heterogeneous substrate, a defect such as
dislocation, or the like, may be increased due to a difference
between lattice constants of a substrate material and a thin film
material. Also, due to a difference between coefficients of thermal
expansion of a substrate material and a thin film material, warping
may occur in the case of a temperature change, resulting in cracks
in the thin film. This may be reduced by using a buffer layer 2002
formed between the substrate 2001 and the GaN-based light emitting
laminate L.
[0202] In order to enhance light or electrical characteristics of
the LED chip before or after the growth of the LED structure, the
substrate 2001 may be fully or partially removed or patterned
during a chip fabrication process.
[0203] For example, in the case of a sapphire substrate, the
substrate may be separated by irradiating a laser onto an interface
between the sapphire substrate and a semiconductor layer through
the substrate, and in the case of a silicon substrate or a silicon
carbide substrate, the substrate may be removed according to a
method such as polishing/etching, or the like.
[0204] Also, in removing the substrate, a different support
substrate may be used, and in this case, the support substrate may
be attached to the opposite side of the original growth substrate
by using a reflective metal or a reflective structure may be
inserted into a middle portion of a bonding layer to enhance light
efficiency of the LED chip.
[0205] In the case of substrate patterning, depressions and
protrusions (or an uneven portion) or a sloped portion is formed on
a main surface (one surface or both surfaces) of the substrate or
on a lateral surface before or after the growth of the LED
structure to thus enhance light extraction efficiency.
[0206] Referring to substrate patterning, an uneven surface or a
sloped surface may be formed on a main surface (one surface or both
surfaces) or a lateral surface of the substrate to enhance light
extraction efficiency. A size of the pattern may be selected from
within the range of 5 nm to 500 .mu.m, and any pattern may be
employed as long as it can enhance light extraction efficiency as a
regular or an irregular pattern. The pattern may have various
shapes such as a columnar shape, a peaked shape, a hemispherical
shape, a polygonal shape, and the like.
[0207] In the case of a sapphire substrate, sapphire is a crystal
having Hexa-Rhombo R3c symmetry, of which lattice constants in
c-axis and a-axis directions are approximately 13.001 .ANG. and
4.758 .ANG., respectively, and has a C-plane (0001), an A-plane
(1120), an R-plane (1102), and the like. In this case, a nitride
thin film may be relatively easily grown on the C-plane of the
sapphire crystal, and because sapphire crystal is stable at high
temperatures, the sapphire substrate is commonly used as a nitride
growth substrate.
[0208] A silicon (Si) substrate may also be used. Because a silicon
(Si) substrate is more appropriate for increasing a diameter and is
relatively low in price, it may be used to facilitate
mass-production. The Si substrate having a (111) plane as a
substrate plane has a 17% difference in a lattice constant from
that of GaN. Thus, a technique for suppressing a generation of a
crystal defect due to the difference between lattice constants is
required. Also, a difference between coefficients of thermal
expansion of silicon and GaN is approximately 56%, for which, thus,
a technique of suppressing warping of a wafer due to the difference
between the coefficients of thermal expansion is required. A warped
wafer may cause cracks in the GaN thin film and make it difficult
to control a process, leading to an increase in a distribution of
light emitting wavelengths in the same wafer, or the like.
[0209] The silicon (Si) substrate absorbs light generated in the
GaN-based semiconductor to lower external quantum efficiency of the
light emitting device. Thus, the substrate may be removed, and a
support substrate such as an Si, Ge, SiAl, ceramic, or metal
substrate, or the like, including a reflective layer, may be
additionally formed to be used.
[0210] [Buffer Layer]
[0211] When a GaN thin film is grown on a heterogeneous substrate
like the Si substrate, dislocation density may be increased due to
a lattice constant mismatch between a substrate material and a thin
film material, and cracks and warpage may be generated due to a
difference between coefficients of thermal expansion.
[0212] In this case, in order to prevent dislocation of and cracks
in the light emitting laminate L, a buffer layer 2002 may be
disposed between the substrate 2001 and the light emitting laminate
L. The buffer layer 2002 may serve to adjust a degree of warpage of
the substrate when an active layer is grown, to reduce a wavelength
distribution of a wafer.
[0213] The buffer layer may be made of AlxInyGal-x-yN
(0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 0.ltoreq.x+y.ltoreq.1),
in particular, GaN, AlN, AlGaN, InGaN, or InGaNAlN, and a material
such as ZrB2, HfB2, ZrN, HfN, TiN, or the like, may also be used.
Also, the buffer layer may be formed by combining a plurality of
layers or by gradually changing a composition.
[0214] The silicon substrate has a significant difference in the
coefficient of thermal expansion from that of GaN. Thus, in the
case of growing a GaN-based thin film on the silicon substrate,
when the GaN thin film is grown at a high temperature and cooled at
room temperature, tensile stress is applied to the GaN thin film
due to the difference between the coefficients of thermal expansion
of the substrate and the thin film, generating cracks. In order to
prevent a generation of cracks, tensile stress is compensated for
by using a method of growing the thin film such that compressive
stress is applied to the thin film while being grown.
[0215] The difference between the lattice constants of silicon (Si)
and GaN increases a possibility of a defect being generated in the
silicon substrate. Thus, in the case of using a silicon substrate,
a buffer layer having a composite structure may be used in order to
control stress for restraining warpage as well as controlling a
defect.
[0216] For example, first, an AlN layer is formed on the substrate
2001. In this case, a material not including gallium (Ga) may be
used in order to prevent a reaction between silicon (Si) and
gallium (Ga). Besides AlN, a material such as SiC, or the like, may
also be used. The AlN layer is grown at a temperature ranging from
400.degree. C. to 1,300.degree. C. by using an aluminum (Al) source
and a nitrogen (N) source. An AlGaN intermediate layer may be
inserted into the middle of GaN between the plurality of AlN layers
to control stress.
[0217] [Light Emitting Laminate]
[0218] The light emitting laminate L having a multilayer structure
of a Group III nitride semiconductor will be described in detail.
The first and second conductivity-type semiconductor layers 2004
and 2006 may be formed of n-type and p-type impurity-doped
semiconductors, respectively.
[0219] However, all the exemplary embodiments are not limited
thereto and, conversely, the first and second conductivity-type
semiconductor layers 2004 and 2006 may be formed of p-type and
n-type impurity-doped semiconductors. For example, the first and
second conductivity-type semiconductor layers 2004 and 2006 may be
made of a Group III nitride semiconductor, e.g., a material having
a composition of AlxInyGal-x-yN (0.ltoreq.x.ltoreq.1,
0.ltoreq.y.ltoreq.1, 0.ltoreq.x+y.ltoreq.1). Of course, the
exemplary embodiment is not limited thereto and the first and
second conductivity-type semiconductor layers 2004 and 2006 may
also be made of a material such as an AlGaInP-based semiconductor
or an AlGaAs-based semiconductor.
[0220] Meanwhile, the first and second conductivity-type
semiconductor layers 2004 and 2006 may have a unilayer structure,
or, alternatively, the first and second conductivity-type
semiconductor layers 2004 and 2006 may have a multilayer structure
including layers having different compositions, thicknesses, and
the like. For example, the first and second conductivity-type
semiconductor layers 2004 and 2006 may have a carrier injection
layer for improving electron and hole injection efficiency, or may
have various types of superlattice structures, respectively.
[0221] The first conductivity-type semiconductor layer 2004 may
further include a current diffusion layer in a region adjacent to
the active layer 2005. The current diffusion layer may have a
structure in which a plurality of InxAlyGa(1-x-y)N layers having
different compositions or different impurity contents are
successively laminated or may have an insulating material layer
partially formed therein.
[0222] The second conductivity-type semiconductor layer 2006 may
further include an electron blocking layer in a region adjacent to
the active layer 2005. The electron blocking layer may have a
structure in which a plurality of InxAlyGa(1-x-y)N layers having
different compositions are laminated or may have one or more layers
including AlyGa(1-y)N. The electron blocking layer has a bandgap
wider than that of the active layer 2005, thus preventing electrons
from being transferred over the second conductivity-type (p-type)
semiconductor layer.
[0223] The light emitting laminate L may be formed by using
metal-organic chemical vapor deposition (MOCVD). In order to
fabricate the light emitting laminate L, an organic metal compound
gas (e.g., trimethyl gallium (TMG), trimethyl aluminum (TMA)) and a
nitrogen-containing gas (ammonia (NH3), or the like) are supplied
to a reaction container in which the substrate 2001 is installed as
reactive gases, the substrate is maintained at a high temperature
ranging from 900.degree. C. to 1,100.degree. C., and while a
gallium nitride-based compound semiconductor is being grown, an
impurity gas is supplied to laminate the gallium nitride-based
compound semiconductor as an undoped n-type or p-type
semiconductor. Silicon (Si) is a well-known n-type impurity, and
p-type impurities include zinc (Zn), cadmium (Cd), beryllium (Be),
magnesium (Mg), calcium (Ca), barium (Ba), and the like. Among
these, magnesium (Mg) and zinc (Zn) may mainly be used.
[0224] Also, the active layer 2005 disposed between the first and
second conductivity-type semiconductor layers 2004 and 2006 may
have a multi-quantum well (MQW) structure in which a quantum well
layer and a quantum barrier layer are alternately laminated. For
example, in the case of a nitride semiconductor, a GaN/InGaN
structure may be used, or a single quantum well (SQW) structure may
also be used.
[0225] [Ohmic-Contact Layer and First and Second Electrodes]
[0226] The ohmic-contact layer 2008 may have a relatively high
impurity concentration to have low ohmic-contact resistance to
lower an operating voltage of the element and enhance element
characteristics. The ohmic-contact layer 2008 may be formed of a
GaN layer, a InGaN layer, a ZnO layer, or a graphene layer.
[0227] The first or second electrode 2009a or 2009b may be made of
a material such as silver (Ag), nickel (Ni), aluminum (Al), rhodium
(Rh), palladium (Pd), iridium (Ir), ruthenium (Ru), magnesium (Mg),
zinc (Zn), platinum (Pt), gold (Au), or the like, and may have a
structure including two or more layers such as Ni/Ag, Zn/Ag, Ni/Al,
Zn/Al, Pd/Ag, Pd/Al, Ir/Ag, Ir/Au, Pt/Ag, Pt/A1, Ni/Ag/Pt, or the
like.
[0228] The LED chip illustrated in FIG. 32 has a structure in which
first and second electrodes 2009a and 2009b face the same surface
as a light extracting surface, but it may also be implemented to
have various other structures, such as a flipchip structure in
which first and second electrodes face a surface opposite to a
light extracting surface, a vertical structure in which first and
second electrodes are formed on mutually opposing surfaces, a
vertical and horizontal structure employing an electrode structure
by forming several vias in a chip as a structure for enhancing
current spreading efficiency and heat dissipation efficiency, and
the like.
Light Emitting Device
Second Example
[0229] In the case of manufacturing a large light emitting device
for high output, an LED chip illustrated in FIG. 33 promoting
current spreading efficiency and heat dissipation efficiency may be
provided.
[0230] As illustrated in FIG. 33, an LED chip 2100 may include a
first conductivity-type semiconductor layer 2104, an active layer
2105, a second conductivity-type semiconductor layer 2106, a second
electrode layer 2107, an insulating layer 2102, a first electrode
layer 2108 and a substrate 2101 sequentially laminated. Here, in
order to be electrically connected to the first conductivity-type
semiconductor layer 2104, the first electrode layer 2108 includes
one or more contact holes H extending from one surface of the first
electrode layer 2108 to at least a partial region of the first
conductivity-type semiconductor layer 2104 and electrically
insulated from the second conductivity-type semiconductor layer
2106 and the active layer 2105. However, the first electrode layer
2108 is not an essential element in the present embodiment.
[0231] The contact hole H extends from an interface of the first
electrode layer 2108, passing through the second electrode layer
2107, the second conductivity-type semiconductor layer 2106, and
the active layer 2105, to the interior of the first
conductivity-type semiconductor layer 2104. The contact hole H
extends to at least an interface between the active layer 2105 and
the first conductivity-type semiconductor layer 2104, and may
extend to a portion of the first conductivity-type semiconductor
layer 2104. However, the contact hole H is formed for electrical
connectivity and current spreading, so the purpose of the presence
of the contact hole H is achieved when it is in contact with the
first conductivity-type semiconductor layer 2104. Thus, it is not
necessary for the contact hole H to extend to an external surface
of the first conductivity-type semiconductor layer 2104.
[0232] The second electrode layer 2107 formed on the second
conductivity-type semiconductor layer 2106 may be made of a
material selected from among silver (Ag), nickel (Ni), aluminum
(Al), rhodium (Rh), palladium (Pd), iridium (Ir), ruthenium (Ru),
magnesium (Mg), zinc (Zn), platinum (Pt), gold (Au), and the like,
in consideration of a light reflecting function and an
ohmic-contact function with the second conductivity-type
semiconductor layer 2106, and may be formed by using a process such
as sputtering, deposition, or the like.
[0233] The contact hole H may have a form penetrating the second
electrode layer 2107, the second conductivity-type semiconductor
layer 2106, and the active layer 2105 so as to be connected to the
first conductivity-type semiconductor layer 2104. The contact hole
H may be formed through an etching process, e.g., inductively
coupled plasma-reactive ion etching (ICP-RIE), or the like.
[0234] The insulating layer 2102 is formed to cover a side wall of
the contact hole H and a surface of the second conductivity-type
semiconductor layer 2106. In this case, at least a portion of the
first conductivity-type semiconductor layer 2104 corresponding to
the bottom of the contact hole H may be exposed. The insulating
layer 2102 may be formed by depositing an insulating material such
as SiO2, SiOxNy, or SixNy. The insulating layer 2102 may be
deposited to have a thickness ranging from about 0.01 .mu.m to 3
.mu.m at a temperature equal to or lower than 500.degree. C.
through a chemical vapor deposition (CVD) process.
[0235] The first electrode layer 2108 including a conductive via
formed by filling a conductive material is formed in the contact
hole H. A plurality of conductive vias may be formed in a single
light emitting device region. The amount of vias and contact areas
thereof may be adjusted such that the area the plurality of vias
occupy on the plane of the regions in which they are in contact
with the second conductivity-type semiconductor layer 2104 ranges
from 1% to 5% of the area of the light emitting device regions. A
radius of the via on the plane of the region in which the via is in
contact with the first conductivity-type semiconductor layer 2104
may range, for example, from 5 .mu.m to 50 .mu.m, and the number of
vias may be 1 to 50 per light emitting device region according to a
width of the light emitting region. Although different according to
a width of the light emitting device region, three or more vias may
be provided. A distance between the vias may range from 100 .mu.m
to 500 .mu.m, and the vias may have a matrix structure including
rows and columns. Further, the distance between vias may range from
150 .mu.m to 450 .mu.m. If the distance between the vias is smaller
than 100 .mu.m, the amount of vias may be relatively increased to
reduce a light emitting area to lower luminous efficiency, and if
the distance between the vias is greater than 500 .mu.m, it may be
difficult to spread a current to degrade luminous efficiency. A
depth of the contact hole H may range from 0.5 .mu.m to 5.0 .mu.m
although it may differ according to a thickness of the second
conductivity-type semiconductor layer and the active layer.
[0236] Subsequently, the substrate 2101 is formed below the first
electrode layer 2108. In this structure, the substrate 2101 may be
electrically connected to the first conductivity-type semiconductor
layer 2104 by a conductive via.
[0237] The substrate 2101 may be made of a material including any
one of Au, Ni, Al, Cu, W, Si, Se, GaAs, SiAl, Ge, SiC, AlN, Al2O3,
GaN, and AlGaN and may be formed through a process such as plating,
sputtering, deposition, bonding, or the like. But all the exemplary
embodiments are not limited thereto.
[0238] In order to reduce contact resistance, the amount, a shape,
a pitch, a contact area with the first and second conductivity-type
semiconductor layers 2104 and 2106, and the like, of the contact
hole H may be appropriately regulated. The contact holes H may be
arranged to have various shapes in rows and columns to improve a
current flow. Here, the second electrode layer 2107 may have one or
more exposed regions in the interface between the second electrode
layer 2017 and the second conductivity-type semiconductor layer
2106, i.e., an exposed region E. An electrode pad unit 2109
connecting an external power source to the second electrode layer
2107 may be provided on the exposed region E.
[0239] In this manner, the LED chip 2100 illustrated in FIG. 33 may
include the light emitting structure having the first and second
main surfaces opposing one another and having the first and second
conductivity-type semiconductor layers 2104 and 2106 providing the
first and second main surfaces, respectively, and the active layer
2105 formed there between, the contact holes H connected to a
region of the first conductivity-type semiconductor layer 2104
through the active layer 2105 from the second main surface, the
first electrode layer 2108 formed on the second main surface of the
light emitting structure and connected to a region of the first
conductivity-type semiconductor layer 2104 through the contact
holes H, and the second electrode layer 2107 formed on the second
main surface of the light emitting structure and connected to the
second conductivity-type semiconductor layer 2106. Here, any one of
the first and second electrodes 2108 and 2107 may be drawn out in a
lateral direction of the light emitting structure.
Light Emitting Device
Third Example
[0240] An LED lighting device provides improved heat dissipation
characteristics, and in terms of overall heat dissipation
performance, an LED chip having a low heating value is preferably
used in a lighting device. As an LED chip satisfying such
requirements, an LED chip including a nano-structure therein
(hereinafter, referred to as a `nano-LED chip`) may be used.
[0241] Such a nano-LED chip includes a recently developed
core/shell type nano-LED chip, which has a low binding density to
generate a relatively low degree of heat, and has increased
luminous efficiency by increasing a light emitting area by
utilizing nano-structures, prevents a degradation of efficiency due
to polarization by obtaining a non-polar active layer, thus
improving drop characteristics such that luminous efficiency is
reduced as an amount of injected current is increased.
[0242] FIG. 34 illustrates a nano-LED chip as another example of an
LED chip that may be employed in the foregoing lighting device.
[0243] As illustrated in FIG. 34, the nano-LED chip 2200 includes a
plurality of nano-light emitting structures N formed on a substrate
2201. In this example, it is illustrated that the nano-light
emitting structure N has a core-shell structure as a rod structure,
but the exemplary embodiment is not limited thereto and the
nano-light emitting structure N may have a different structure such
as a pyramid structure.
[0244] The nano-LED chip 2200 includes a base layer 2202 formed on
the substrate 2201. The base layer 2202 is a layer providing a
growth surface for the nano-light emitting structure N, which may
be a first conductivity-type semiconductor. A mask layer 2203
having an open area for the growth of the nano-light emitting
structure N (in particular, the core) may be formed on the base
layer 2202. The mask layer 2203 may be made of a dielectric
material such as SiO2 or SiNx.
[0245] In the nano-light emitting structure N, a first
conductivity-type nano core 2204 is formed by selectively growing a
first conductivity-type semiconductor by using the mask layer 2203
having an open area, and an active layer 2205 and a second
conductivity-type semiconductor layer 2206 are formed as shell
layers on a surface of the nano core 2204. Accordingly, the
nano-light emitting structure N may have a core-shell structure in
which the first conductivity-type semiconductor is a nano core and
the active layer 2205 and the second conductivity-type
semiconductor layer 2206 enclosing the nano core are shell
layers.
[0246] The nano-LED chip 2200 includes a filler material 2207
filling spaces between the nano-light emitting structures N. The
filler material 2207 may be employed in order to structurally
stabilize and optically improve the nano-light emitting structures
N. The filler material 2207 may be made of a transparent material
such as SiO2, but all the exemplary embodiments are not limited
thereto. An ohmic-contact layer 2208 may be formed on the
nano-light emitting structures N and connected to the second
conductivity-type semiconductor layer 2206. The nano-LED chip 2200
includes the base layer 2202 formed of the first conductivity-type
semiconductor and first and second electrodes 2209a and 2209b
connected to the base layer 2202 and the ohmic-contact layer 1608,
respectively.
[0247] By forming the nano-light emitting structures N such that
they have different diameters, components, and doping densities,
light having two or more different wavelengths may be emitted from
the single element. By appropriately adjusting light having
different wavelengths, white light may be implemented without using
phosphors in the single element, and light having various colors or
white light having different color temperatures may be implemented
by combining a different LED chip to the foregoing element or
combining wavelength conversion materials such as phosphors.
Light Emitting Device
Fourth Example
[0248] FIG. 35 illustrates a semiconductor light emitting device
2300 having an LED chip 2310 mounted on a mounting substrate 2320,
as a light source that may be employed in the foregoing lighting
device.
[0249] The semiconductor light emitting device 2300 illustrated in
FIG. 35 includes the LED chip 2310. The LED chip 2310 is presented
as an LED chip different from that of the example described
above.
[0250] The LED chip 2310 includes a light emitting laminate L
disposed on one surface of the substrate 2301 and first and second
electrodes 2308a and 2308b disposed on the opposite side of the
substrate 2301 based on the light emitting laminate L. Also, the
LED chip 2310 includes an insulating layer 2303 covering the first
and second electrodes 2308a and 2308b.
[0251] The first and second electrodes 2308a and 2308b may include
first and second electrode pads 2319a and 2319b electrically
connected thereto by electrical connection units 2309a and
2309b.
[0252] The light emitting laminate L may include a first
conductivity-type semiconductor layer 2304, an active layer 2305,
and a second conductivity-type semiconductor layer 2306
sequentially disposed on the substrate 2301. The first electrode
2308a may be provided as a conductive via connected to the first
conductivity-type semiconductor layer 2304 through the second
conductivity-type semiconductor layer 2306 and the active layer
2305. The second electrode 2308b may be connected to the second
conductivity-type semiconductor layer 2306.
[0253] A plurality of conductive vias may be formed in a single
light emitting device region. The amount of vias and contact areas
thereof may be adjusted such that the area of the plurality of vias
occupying on the plane of the regions in which they are in contact
with the second conductivity-type semiconductor layer 2304 ranges
from 1% to 5% of the area of the light emitting device regions. A
radius of the via on the plane of the region in which the via is in
contact with the first conductivity-type semiconductor layer 2304
may range, for example, from Sum to 50 .mu.m, and the number of
vias may be 1 to 50 per light emitting device region, according to
a width of the light emitting region. Although different, according
to a width of the light emitting device region, three or more vias
may be provided. A distance between the vias may range from 100
.mu.m to 500 .mu.m, and the vias may have a matrix structure
including rows and columns. Further, the distance between vias may
range from 150 .mu.m to 450 .mu.m. If the distance between the vias
is smaller than 100 .mu.m, the amount of vias is increased to
relatively reduce a light emitting area to lower luminous
efficiency, and if the distance between the vias is greater than
500 .mu.m, it may be difficult to spread a current to degrade
luminous efficiency. A depth of the vias may range from 0.5 .mu.m
to 5.0 .mu.m, although it may differ according to a thickness of
the second conductivity-type semiconductor layer 2306 and the
active layer 2305.
[0254] The first and second electrodes 2308a and 2308b are formed
by depositing a conductive ohmic-material on the light emitting
laminate L. The first and second electrodes 2308a and 2308b may
include at least one of Ag, Al, Ni, Cr, Cu, Au, Pd, Pt, Sn, Ti, W,
Rh, Ir, Ru, Mg, Zn, and alloys thereof. For example, the second
electrode 2308b may be formed as a silver (Ag) ohmic-electrode
layer laminated with regard to the second conductivity-type
semiconductor layer 2306. The silver (Ag) ohmic-electrode layer may
also serve as a light reflective layer. A single layer made of
nickel (NI), titanium (Ti), platinum (Pt), tungsten (W), or a layer
of alloys thereof may alternatively laminated selectively on the
silver (Ag) layer. In detail, an Ni/Ti layer, a TiW/Pt layer, or a
Ti/W layer may be laminated on the silver (Ag) layer or these
layers may be alternately laminated on the silver (Ag) layer.
[0255] The first electrode 2308a may be formed by laminating a
chromium (Cr) layer and sequentially laminating Au/Pt/Ti layers
thereon with regard to the first conductivity-type semiconductor
layer 2304, or may be formed by laminating an Al layer and
sequentially laminating Ti/Ni/Au layers thereon with regard to the
second conductivity-type semiconductor layer 2306. Besides the
foregoing embodiment, the first and second electrodes 2308a and
2308b may employ various materials or lamination structures in
order to enhance ohmic characteristics or reflective
characteristics.
[0256] The insulating layer 2303 has an open area exposing at least
portions of the first and second electrodes 2308a and 2308b, and
the first and second electrode pads 2319a and 2319b may be
connected to the first and second electrodes 2308a and 2308b. The
insulating layer 2303 may be deposited to have a thickness ranging
from 0.01 .mu.m to 3 .mu.m at a temperature equal to or lower than
500.degree. C. through a CVD process.
[0257] The first and second electrodes 2308a and 2308b may be
disposed in the same direction and may be mounted as a so-called
flip-chip on a lead frame as described hereinafter.
[0258] In particular, the first electrode 2308a may be connected to
the first electrical connection unit 2309a by a conductive via
connected to the first conductivity-type semiconductor layer 2304
through the second conductivity-type semiconductor layer 2306 and
the active layer 2305 within the light emitting laminate L.
[0259] The amount, a shape, a pitch, a contact area with the first
conductivity-type semiconductor layer 2304, and the like, of the
conductive via and the first electrical connection unit 2309a may
be appropriately regulated in order to lower contact resistance,
and the conductive via and the first electrical connection unit
2309a may be arranged in a row and in a column to improve current
flow.
[0260] Another electrode structure may include the second electrode
2308b directly formed on the second conductivity-type semiconductor
layer 2306 and the second electrical connection unit 2309b formed
on the second electrode 2308b. In addition to having a function of
forming electrical-ohmic connection with the second
conductivity-type semiconductor layer 2306, the second electrode
2308b may be made of a light reflective material, whereby, as
illustrated in FIG. 35, in a state in which the LED chip 2310 is
mounted as a so-called flip chip structure, light emitted from the
active layer 2305 can be effectively emitted in a direction of the
substrate 2301. Of course, the second electrode 2308b may be made
of a light-transmissive conductive material such as a transparent
conductive oxide, according to a main light emitting direction.
[0261] The two electrode structures as described above may be
electrically separated by the insulating layer 2303. The insulating
layer 2303 may be made of any material as long as it has
electrically insulating properties. Namely, the insulating layer
2303 may be made of any material having electrically insulating
properties, and here, a material having a low degree of light
absorption is used. For example, a silicon oxide or a silicon
nitride such as SiO2, SiOxNy, SixNy, or the like, may be used. A
light reflective filler may be dispersed in the light-transmissive
material to form a light reflective structure.
[0262] The first and second electrode pads 2319a and 2319b may be
connected to the first and second electrical connection units 2309a
and 2309b to serve as external terminals of the LED chip 2310,
respectively. For example, the first and second electrode pads
2319a and 2319b may be made of gold (Au), silver (Ag), aluminum
(Al), titanium (Ti), tungsten (W), copper (Cu), tin (Sn), nickel
(Ni), platinum (Pt), chromium (Cr), NiSn, TiW, AuSn, or a eutectic
metal thereof. In this case, when the LED chip 2310 is mounted on
the mounting substrate 2320, the first and second electrode pads
2319a and 2319b may be bonded by using the eutectic metal, so
solder bumps generally required for flip chip bonding may not be
used. The use of a eutectic metal advantageously obtains superior
heat dissipation effects in the mounting method as compared to the
case of using solder bumps. In this case, in order to obtain
excellent heat dissipation effects, the first and second electrode
pads 2319a and 2319b may be formed to occupy a relatively large
area.
[0263] The substrate 2301 and the light emitting laminate L may be
understood with reference to content described above with reference
to FIG. 32 unless otherwise described. Also, although not shown, a
buffer layer may be formed between the light emitting laminate L
and the substrate 2301. The buffer layer may be employed as an
undoped semiconductor layer made of a nitride, or the like, to
alleviate lattice defects of the light emitting laminate L grown
thereon.
[0264] The substrate 2301 may have first and second main surfaces
opposing one another, and an uneven structure C (i.e., depressions
and protrusions) may be formed on at least one of the first and
second main surfaces. The uneven structure C formed on one surface
of the substrate 2301 may be formed by etching a portion of the
substrate 2301 so as to be made of the same material as that of the
substrate. Alternatively, the uneven structure C may be made of a
heterogeneous material different from that of the substrate
2301.
[0265] In the exemplary embodiment, because the uneven structure C
is formed on the interface between the substrate 2301 and the first
conductivity-type semiconductor layer 2304, the paths of light
emitted from the active layer 2305 may be widely varied, and thus,
a light absorption ratio of light absorbed within the semiconductor
layer can be reduced and a light scattering ratio can be increased,
increasing light extraction efficiency.
[0266] In detail, the uneven structure C may be formed to have a
regular or irregular shape. The heterogeneous material used to form
the uneven structure C may be a transparent conductor, a
transparent insulator, or a material having excellent reflectivity.
Here, as the transparent insulator, a material such as SiO2, SiNx,
Al2O3, HfO, TiO2, or ZrO may be used.
[0267] As the transparent conductor, a transparent conductive oxide
(TCO) such as ZnO, an indium oxide containing an additive (e.g.,
Mg, Ag, Zn, Sc, Hf, Zr, Te, Se, Ta, W, Nb, Cu, Si, Ni, Co, Mo, Cr,
Sn), or the like, may be used. As the reflective material, silver
(Ag), aluminum (Al), or a distributed Bragg reflector (DBR)
including multiple layers having different refractive indices, may
be used. However, the exemplary embodiment is not limited
thereto.
[0268] The substrate 2301 may be removed from the first
conductivity-type semiconductor layer 2304. To remove the substrate
2301, a laser lift-off (LLO) process using a laser, an etching or a
polishing process may be used. Also, after the substrate 2301 is
removed, depressions and protrusions may be formed on the surface
of the first conductivity-type semiconductor layer 2304.
[0269] As illustrated in FIG. 35, the LED chip 2310 is mounted on
the mounting substrate 2320. The mounting substrate 2320 includes a
first upper electrode layer 2312a, a first lower electrode layer
2312b, a second upper electrode layer 2313a and a second lower
electrode layer 2313b formed on upper and lower surfaces of the
substrate body 2311, and vias 2313 penetrating the substrate body
2311 to connect the upper and lower electrode layers. The substrate
body 2311 may be made of a resin, a ceramic, or a metal, and the
upper and lower electrode layers 2312a, 2313a, 2312b and 2313b may
be a metal layer made of gold (Au), copper (Cu), silver (Ag), or
aluminum (Al).
[0270] Of course, the substrate on which the foregoing LED chip
2310 is mounted is not limited to the configuration of the mounting
substrate 2320 illustrated in FIG. 35, and any substrate having a
wiring structure for driving the LED chip 2310 may be employed. For
example, the substrate may be any one of the substrates of FIGS. 25
through 31, and may be provided as a package structure in which an
LED chip is mounted on a package body having a pair of lead
frames.
Other Examples of Light Emitting Device
[0271] LED chips having various structures other than that of the
foregoing LED chip described above may also be used. For example,
an LED chip in which surface-plasmon polaritons (SPP) are formed in
a metal-dielectric boundary of an LED chip to interact with quantum
well excitons, thus obtaining significantly improved light
extraction efficiency, may also be advantageously used.
[0272] Meanwhile, the light emitting device 420 may be configured
to include at least one of a light emitting device emitting white
light by combining green, red, and orange phosphors with a blue LED
chip and a purple, blue, green, red, and infrared light emitting
device. In this case, the light emitting device 420 may have a
color rendering index (CRI) adjusted to range from a sodium-vapor
lamp (color rending index: 40) to a sunlight level (color rendering
index: 100), or the like, and have a color temperature ranging from
about 2000K to 20000K level to generate various types of white
light. The light emitting device 420 may generate visible light
having purple, blue, green, red, orange colors, or infrared light
to adjust an illumination color according to a surrounding
atmosphere or mood. Also, the light source apparatus may generate
light having a special wavelength stimulating plant growth.
[0273] White light generated by applying yellow, green, red
phosphors to a blue LED chip and combining at least one of green
and red LEDs thereto may have two or more peak wavelengths and may
be positioned in a segment linking (x,y) coordinates (0.4476,
0.4074), (0.3484, 0.3516), (0.3101, 0.3162), (0.3128, 0.3292),
(0.3333, 0.3333) of a CIE 1931 chromaticity diagram illustrated in
FIG. 36. Alternatively, white light may be positioned in a region
surrounded by a spectrum of black body radiation and the segment. A
color temperature of white light corresponds to a range from 2000K
to 20000K.
[0274] Phosphors may have the following empirical formula and
colors.
[0275] Oxide system: Yellow and green Y3Al5012:Ce, Tb3Al5O12:Ce,
Lu3Al5O12:Ce
[0276] Silicate system: Yellow and green (Ba,Sr)2SiO4:Eu, yellow
and orange (Ba,Sr)3SiO5:Ce
[0277] Nitride system: Green .beta.-SiAlON:Eu, yellow L3Si6O11:Ce,
orange .alpha.-SiAlON:Eu, red CaAlSiN3:Eu, Sr2Si5N8:Eu,
SrSiAl4N7:Eu
[0278] Fluoride system: KSF system red K2SiF6:Mn4+
[0279] Phosphor compositions should be basically conformed with
Stoichiometry, and respective elements may be substituted with
different elements of respective groups of the periodic table. For
example, strontium (Sr) may be substituted with barium (Ba),
calcium (Ca), magnesium (Mg), or the like, of alkali earths, and
yttrium (Y) may be substituted with terbium (Tb), Lutetium (Lu),
scandium (Sc), gadolinium (Gd), or the like. Also, europium (Eu),
an activator, may be substituted with cerium (Ce), terbium (Tb),
praseodymium (Pr), erbium (Er), ytterbium (Yb), or the like,
according to an energy level, and an activator may be applied alone
or a coactivator, or the like, may be additionally applied to
change characteristics.
[0280] Also, materials such as quantum dots, or the like, may be
applied as materials that replace phosphors, and phosphors and
quantum dots may be used in combination or alone in an LED.
[0281] A quantum dot may have a structure including a core (3 to 10
nm) such as CdSe, InP, or the like, a shell (0.5 to 2 nm) such as
ZnS, ZnSe, or the like, and a ligand for stabilizing the core and
the shell, and may implement various colors according to sizes.
[0282] Table 1 below shows types of phosphors in applications
fields of white light emitting devices using a blue LED (440 nm to
460 nm).
TABLE-US-00001 TABLE 1 Purpose Phosphors LED TV BLU
.beta.-SiAlON:Eu2+ (Ca,Sr)AlSiN3:Eu2+ L3Si6O11:Ce3+ K2SiF6:Mn4+
Lighting Lu3Al5O12:Ce3+ Ca-.alpha.-SiAlON:Eu2+ L3Si6N11:Ce3+
(Ca,Sr)AlSiN3:Eu2+ Y3Al5O12:Ce3+ K2SiF6:Mn4+ Side View
Lu3Al5O12:Ce3+ (Mobile, Note PC) Ca-.alpha.-SiAlON:Eu2+
L3Si6N11:Ce3+ (Ca,Sr)AlSiN3:Eu2+ Y3Al5O12:Ce3+
(Sr,Ba,Ca,Mg)2SiO4:Eu2+ K2SiF6:Mn4+ Electrical component
Lu3Al5O12:Ce3+ (Head Lamp, etc.) Ca-.alpha.-SiAlON:Eu2+
L3Si6N11:Ce3+ (Ca,Sr)AlSiN3:Eu2+ Y3Al5O12:Ce3+ K2SiF6:Mn4+
[0283] Phosphors or quantum dots may be applied by using at least
one of a method of spraying them on a light emitting device, a
method of covering as a film, and a method of attaching as a sheet
of ceramic phosphor, or the like.
[0284] As the spraying method, dispensing, spray coating, or the
like, is generally used, and dispensing includes a pneumatic method
and a mechanical method such as a screw fastening scheme, a linear
type fastening scheme, or the like. Through a jetting method, an
amount of dotting may be controlled through a very small amount of
discharging and color coordinates (or chromaticity) may be
controlled there through. In the case of a method of collectively
applying phosphors on a wafer level or on a mounting board on which
an LED is mounted, productivity can be enhanced and a thickness can
be easily controlled.
[0285] The method of directly covering a light emitting device with
phosphors or quantum dots as a film may include electrophoresis,
screen printing, or a phosphor molding method, and these methods
may have a difference according to whether a lateral surface of a
chip is required to be coated or not.
[0286] Meanwhile, in order to control efficiency of a long
wavelength light emitting phosphor re-absorbing light emitted in a
short wavelength, among two types of phosphors having different
light emitting wavelengths, two types of phosphor layer having
different light emitting wavelengths may be provided, and in order
to minimize re-absorption and interference of chips and two or more
wavelengths, a DBR (ODR) layer may be included between respective
layers. In order to form a uniformly coated film, after a phosphor
is fabricated as a film or a ceramic form and attached to a chip or
a light emitting device.
[0287] In order to differentiate light efficiency and light
distribution characteristics, a light conversion material may be
positioned in a remote form, and in this case, the light conversion
material may be positioned together with a material such as a
light-transmissive polymer, glass, or the like, according to
durability and heat resistance.
[0288] A phosphor applying technique plays the most important role
in determining light characteristics in an LED device, so
techniques of controlling a thickness of a phosphor application
layer, a uniform phosphor distribution, and the like, have been
variously researched.
[0289] A quantum dot (QD) may also be positioned in a light
emitting device in the same manner as that of a phosphor, and may
be positioned in glass or a light-transmissive polymer material to
perform optical conversion.
[0290] In the present exemplary embodiment, the light emitting
device is illustrated as being a single package unit including an
LED chip therein, but all exemplary embodiments are not limited
thereto. For example, the light emitting device 120 may be an LED
chip itself. In this case, the LED chip may be a COB type chip and
may be mounted on the board and directly electrically connected to
the board through a flip chip bonding method or a wire bonding
method.
[0291] Also, a plurality of light emitting devices may be arranged
on the board. In this case, the light emitting devices may be the
same type of light emitting devices generating light having the
same wavelength or may be various types of light emitting devices
generating different wavelengths of light. In the present exemplary
embodiment, it is illustrated that a plurality of light emitting
devices are arranged, but all exemplary embodiments are not limited
thereto and a single light emitting device may be provided.
[0292] The lighting apparatus using the LED as described above may
be classified as an indoor lighting apparatus and an outdoor
lighting apparatus according to the purpose thereof. The indoor LED
lighting apparatus may include a lamp, a fluorescent lamp
(LED-tube), a flat panel type lighting apparatus replacing an
existing lighting fixture (retrofit), and the outdoor LED lighting
apparatus may include a streetlight, a security light, a flood
light, a scene lamp, a traffic light, and the like.
[0293] Also, the lighting apparatus using the LED may be utilized
as an internal or external light source of a vehicle. As an
internal light source, the lighting apparatus using the LED may be
used as an indoor light of a vehicle, a reading light, or as
various dashboard light sources. As an external light source, the
lighting apparatus using the LED may be used as for a light source
in vehicle lighting fixture such as a headlight, a brake light, a
turn signal lamp, a fog light, a running light, and the like.
[0294] In addition, the LED lighting apparatus may also be
applicable as a light source used in robots or various mechanic
facilities. In particular, LED lighting using a particular
wavelength band may accelerate plant growth, and stabilize a user's
mood or treat a disease using sensitivity (or emotional)
illumination (or lighting).
[0295] A lighting system using the lighting device as described
above with reference to FIGS. 37 to 40 will be described. The
lighting system according to the present embodiment may be able to
provide a lighting device having sensitivity (or emotional)
illumination that is able to automatically adjust a color
temperature according to a surrounding environment (e.g.,
temperature and humidity conditions) and to suit human needs,
rather than serving as a simple illumination device.
[0296] FIG. 37 is a block diagram schematically illustrating a
lighting system according to an embodiment of the present
disclosure.
[0297] Referring to FIG. 37, a lighting system 10000 according to
an embodiment of the present disclosure may include a sensing unit
10010, a control unit 10020, a driving unit 10030, and a lighting
unit 10040.
[0298] The sensing unit 10010 may be installed in an indoor or
outdoor area, and may have a temperature sensor 10011 and a
humidity sensor 10012 to measure at least one air condition among
ambient temperature and humidity. The sensing unit 10010 transmits
the measured at least one air condition, i.e., at least one of
temperature and humidity, to the control unit 10020 electrically
connected thereto.
[0299] The control unit 10020 may compare the temperature and
humidity of the measured air with air condition settings (a
temperature and a humidity range) previously set by a user, and
determine a color temperature of the lighting unit 10040
corresponding to the air condition according to the comparison
results. The control unit 10020 is electrically connected to the
driving unit 10030, and controls the driving unit 10030 to drive
the lighting unit 10040.
[0300] The lighting unit 10040 operates according to power supplied
by the driving unit 1003. The lighting unit 10040 may include at
least one lighting device illustrated in FIGS. 1, 8 and 15. For
example, as illustrated in FIG. 38, the lighting unit 10040 may
include a first lighting device 10041 and a second lighting device
10042 having different color temperatures, and each of the lighting
devices 10041 and 10042 may include a plurality of light emitting
devices emitting the same white light.
[0301] The first lighting device 10041 may emit white light having
a first color temperature, and the second lighting device 10042 may
emit white light having a second color temperature. In this case,
the first color temperature may be lower than the second color
temperature. Conversely, the first color temperature may be higher
than the second color temperature. Here, white light having a
relatively low color temperature corresponds to warm white light,
and white light having a relatively high color temperature
corresponds to cold white light. When power is supplied to the
first and second lighting devices 10041 and 10042, the first and
second lighting devices 10041 and 10042 emit white light having a
first color temperature and a second color temperature,
respectively, and the respective white light beams are mixed to
implement white light having a color temperature determined by the
control unit 10020.
[0302] In detail, in a case in which the first color temperature is
lower than the second color temperature, if a color temperature
determined by the control unit 10020 is relatively high, a quantity
of light of the first lighting device 10041 may be reduced and that
of the second lighting device 10042 may be increased to implement
mixed white light having the predetermined color temperature.
Conversely, when the predetermined color temperature is relatively
low, a quantity of the first lighting device 10041 may be increased
and that of the second lighting device 10042 may be reduced to
implement mixed white light having the predetermined color
temperature. Here, the quantity of light of the respective lighting
devices 10041 and 10042 may be implemented by adjusting a quantity
of light of the entire light emitting devices by regulating power,
or may be implemented by adjusting the amount of light emitting
devices driven.
[0303] FIG. 39 is a flow chart illustrating a method for
controlling the lighting system illustrated in FIG. 37. Referring
to FIG. 39, first, a user sets a color temperature according to a
temperature and humidity range through the control unit 10020 (S
10). The set temperature and humidity data is stored in the control
unit 10020.
[0304] In general, when a color temperature is equal to or more
than 6000K, a color providing a cool feeling, such as blue, may be
produced, and when a color temperature is less than 4000K, a color
providing a warm feeling, such as red, may be produced. Thus, in
the present embodiment, when a temperature and humidity exceed
20.degree. C. and 60%, respectively, the user may set the lighting
unit 10040 to be turned on to have a color temperature higher than
6000K through the control unit 10020, when a temperature and
humidity range from 10.degree. C. to 20.degree. C. and 40% to 60%,
respectively, the user may set the lighting unit 10040 to be turned
on to have a color temperature ranging from 4000K to 6000K through
the control unit 10020, and when a temperature and humidity are
lower than 10.degree. C. and 40%, respectively, the user may set
the lighting unit 10040 to be turned on to have a color temperature
lower than 4000K through the control unit 10020.
[0305] Next, the sensing unit 10010 measures at least one condition
among ambient temperature and humidity (S20). The temperature and
humidity measured by the sensing unit 10010 are transmitted to the
control unit 10020.
[0306] Subsequently, the control unit 10020 compares the
measurement values transmitted from the sensing unit 10010 with
pre-set values (S30). Here, the measurement values are temperature
and humidity data measured by the sensing unit 10010 and the
pre-set values are temperature and humidity values previous set by
the user and stored in the control unit 10020. Namely, the control
unit 10020 compares the measured temperature and humidity levels
with pre-set temperature and humidity levels.
[0307] The control unit 10020 determines whether the measurement
values satisfy pre-set value ranges (S40). When the measurement
values satisfy the pre-set value ranges, the control unit 10020
maintains a current color temperature, and continues to measure
temperature and humidity (S20). Meanwhile, when the measurement
values do not satisfy the pre-set value ranges, the control unit
10020 detects pre-set values corresponding to the measurement
values and determines a corresponding color temperature (S50).
Thereafter, the control unit 10020 controls the driving unit 10030
to drive the lighting unit 10040 to have the predetermined color
temperature.
[0308] Then, the driving unit 10030 drives the lighting unit 10040
to have the predetermined color temperature (S60). Namely, the
driving unit 10030 supplies required power to drive the lighting
unit 10040 to implement the predetermined color temperature.
Accordingly, the lighting unit 10040 may be adjusted to have a
color temperature corresponding to the temperature and humidity
previously set by the user according to ambient temperature and
humidity.
[0309] In this manner, the lighting system is able to automatically
regulate a color temperature of the indoor lighting unit according
to changes in ambient temperature and humidity, thereby satisfying
human moods varied according to changes in the surrounding natural
environment and providing psychological stability.
[0310] FIG. 40 is a view schematically illustrating the use of the
lighting system illustrated in FIG. 37. As illustrated in FIG. 40,
the lighting unit 10040 may be installed on the ceiling as an
indoor lamp. Here, the sensing unit 10010 may be implemented as a
separate device and installed on an outer wall in order to measure
outdoor temperature and humidity. The control unit 10020 may be
installed in an indoor area to allow the user to easily perform
setting and ascertainment operations. However, the lighting system
according to an exemplary embodiment is not limited thereto and may
be installed on the wall in the place of an interior illumination
device or may be applicable to a lamp, such as a desk lamp, or the
like, that can be used in indoor and outdoor areas.
[0311] Another example of a lighting system using the foregoing
lighting device will be described with reference to FIGS. 41
through 44. The lighting system according to the present embodiment
may automatically perform a predetermined control by detecting a
motion of a monitored target and an intensity of illumination at a
location of the monitored target and automatically perform the
predetermined control.
[0312] FIG. 41 is a block diagram of a lighting system according to
another exemplary embodiment.
[0313] Referring to FIG. 41, a lighting system 10000' according to
the present embodiment includes a wireless sensing module 10100 and
a wireless lighting controlling apparatus 10200.
[0314] The wireless sensing module 10100 may include a motion
sensor 10100, an illumination intensity sensor 10120 sensing an
intensity of illumination, and a first wireless communications unit
generating a wireless signal that includes a motion sensing signal
from the motion sensor 10110 and an illumination intensity sensing
signal from the illumination intensity sensor 10120 and that
complies with a predetermined communications protocol, and
transmitting the same. The first wireless communications unit may
be configured as a first ZigBee communications unit 10130
generating a ZigBee signal that complies with a pre-set
communications protocol and transmitting the same.
[0315] The wireless lighting controlling apparatus 10200 may
include a second wireless communications unit receiving a wireless
signal from the first wireless communications unit and restoring a
sensing signal, a sensing signal analyzing unit 10220 analyzing the
sensing signal from the second wireless communications unit, and an
operation control unit 10230 performing a predetermined control
based on analysis results from the sensing signal analyzing unit
10220. The second wireless communications unit may be configured as
a second ZigBee communications unit 10210 receiving a ZigBee signal
from the first ZigBee communications unit and restoring a sensing
signal.
[0316] FIG. 42 is a view illustrating a format of a ZigBee signal
according to an exemplary embodiment.
[0317] Referring to FIG. 33, the ZigBee signal from the first
ZigBee communications unit 10130 may include channel information
(CH) defining a communications channel, a wireless network
identification (ID) information (PAN_ID) defining a wireless
network, a device address (Ded_Add) designating a target device,
and sensing data including the motion and illumination intensity
signal.
[0318] Also, the ZigBee signal from the second ZigBee
communications unit 10210 may include channel information (CH)
defining a communications channel, a wireless network
identification (ID) information (PAN_ID) defining a wireless
network, a device address (Ded_Add) designating a target device,
and sensing data including the motion and illumination intensity
signal.
[0319] The sensing signal analyzing unit 10220 may analyze the
sensing signal from the second ZigBee communications unit 10210 to
detect a satisfied condition, among a plurality of conditions,
based on the sensed motion and the sensed intensity of
illumination.
[0320] Here, the operation control unit 10230 may set a plurality
of controls based on a plurality of conditions that are previously
set by the sensing signal analyzing unit 10220, and perform a
control corresponding to the condition detected by the sensing
signal analyzing unit 10220.
[0321] FIG. 43 is a view illustrating the sensing signal analyzing
unit and the operation control unit according to an exemplary
embodiment. Referring to FIG. 43, for example, the sensing signal
analyzing unit 10220 may analyze the sensing signal from the second
ZigBee communications unit 10210 and detect a satisfied condition
among first, second, and third conditions (condition 1, condition
2, and condition 3), based on the sensed motion and sensed
intensity of illumination.
[0322] In this case, the operation control unit 10230 may set
first, second and third controls (control 1, control 2, and control
3) corresponding to the first, second, and third conditions
(condition 1, condition 2, and condition 3) previously set by the
sensing signal analyzing unit 10220, and perform a control
corresponding to the condition detected by the sensing signal
analyzing unit 10220.
[0323] FIG. 44 is a flow chart illustrating an operation of a
wireless lighting system according to an exemplary embodiment.
[0324] In FIG. 44, in operation S110, the motion sensor 10110
detects a motion. In operation S120, the illumination intensity
sensor 10120 detects an intensity of illumination. Operation S200
is a process of transmitting and receiving a ZigBee signal.
Operation 5200 may include operation S130 of transmitting a ZigBee
signal by the first ZigBee communications unit 10130 and operation
S210 of receiving the ZigBee signal by the second ZigBee
communications unit 10210. In operation S220, the sensing signal
analyzing unit 10220 analyzes a sensing signal. In operation S230,
the operation control unit 10230 performs a predetermined control.
In operation S240, whether the lighting system is terminated is
determined.
[0325] Operations of the wireless sensing module and the wireless
lighting controlling apparatus according to an exemplary embodiment
will be described with reference to FIGS. 41 through 44.
[0326] First, the wireless sensing module 10100 of the wireless
lighting system according to an exemplary embodiment will be
described with reference to FIGS. 41, 42, and 44. The wireless
lighting system 10100 according to an exemplary embodiment is
installed in a location in which a lighting device is installed, to
detect a current intensity of illumination of the current of the
lighting device and detect human motion near the lighting
device.
[0327] Namely, the motion sensor 10110 of the wireless sensing
module 10100 is configured as an infrared sensor, or the like,
capable of sensing a human. The motion sensor 10100 senses a motion
and provides the same to the first ZigBee communications unit 10130
(S110 in FIG. 44). The illumination intensity sensor 10120 of the
wireless sensing module 10100 senses an intensity of illumination
and provides the same to the first ZigBee communications unit 10130
(S120).
[0328] Accordingly, the first ZigBee communications unit 10130
generates a ZigBee signal that includes the motion sensing signal
from the motion sensor 10100 and the illumination intensity sensing
signal from the illumination intensity sensor 10120 and that
complies with a pre-set communications protocol, and transmits the
generated ZigBee signal wirelessly (S130).
[0329] Referring to FIG. 42, the ZigBee signal from the first
ZigBee communications unit 10130 may include channel information
(CH) defining a communications channel, a wireless network
identification (ID) information (PAN_ID) defining a wireless
network, a device address (Ded_Add) designating a target device,
and sensing data, and here, the sensing data includes a motion
value and an illumination intensity value.
[0330] Next, the wireless lighting controlling apparatus 10200 of
the wireless lighting system according to an exemplary embodiment
will be described with reference to FIGS. 41 through 44. The
wireless lighting controlling apparatus 10200 of the wireless
lighting system according to an exemplary embodiment may control a
predetermined operation according to an illumination intensity
value and a motion value included in a ZigBee signal from the
wireless sensing module 10100.
[0331] Namely, the second ZigBee communications unit 10210 of the
wireless lighting controlling apparatus 10200 according to an
exemplary embodiment receives a ZigBee signal from the first ZigBee
communications unit 10130, restores a sensing signal therefrom, and
provides the restored sensing signal to the sensing signal
analyzing unit 10200 (S210 in FIG. 44).
[0332] Referring to FIG. 42, the ZigBee signal from the second
ZigBee communications unit 10210 may include channel information
(CH) defining a communications channel, a wireless network
identification (ID) information (PAN_ID) defining a wireless
network, a device address (Ded_Add) designating a target device,
and sensing data. A wireless network may be identified based on the
channel information (CH) and the wireless network ID information
(PAN_ID), and a sensed device may be recognized based on the device
address. The sensing signal includes the motion value and the
illumination intensity value.
[0333] Also, referring to FIG. 41, the sensing signal analyzing
unit 10220 analyzes the illumination intensity value and the motion
value included in the sensing signal from the second ZigBee
communications unit 10210 and provides the analysis results to the
operation control unit 10230 (S220 in FIG. 44).
[0334] Accordingly, the operation control unit 10230 may perform a
predetermined control according to the analysis results from the
sensing signal analyzing unit 10220 (S230).
[0335] The sensing signal analyzing unit 10220 may analyze the
sensing signal form the second ZigBee communications unit 10210 and
detect a satisfied condition, among a plurality of conditions,
based on the sensed motion and the sensed intensity of
illumination. Here, the operation control unit 10230 may set a
plurality of controls corresponding to the plurality of conditions
set in advance by the sensing signal analyzing unit 10220, and
perform a control corresponding to the condition detected by the
sensing signal analyzing unit 10220.
[0336] For example, referring to FIG. 43, the sensing signal
analyzing unit 10220 may detect a satisfied condition among the
first, second, and third conditions (condition 1, condition 2, and
condition 3) based on the sensed human motion and the sensed
intensity of illumination by analyzing the sensing signal from the
second ZigBee communications unit 10210.
[0337] In this case, the operation control unit 10230 may set
first, second, and third controls (control 1, control 2, and
control 3) corresponding to the first, second, and third conditions
(condition 1, condition 2, and condition 3) set in advance by the
sensing signal analyzing unit 10220, and perform a control
corresponding to the condition detected by the sensing signal
analyzing unit 10220.
[0338] For example, when the first condition (condition 1)
corresponds to a case in which human motion is sensed at a front
door and an intensity of illumination at the front door is not low
(not dark), the first control may turn off all predetermined lamps.
When the second condition (condition 2) corresponds to a case in
which human motion is sensed at the front door and an intensity of
illumination at the front door is low (dim), the second control may
turn on some pre-set lamps (i.e., some lamps at the front door and
some lamps in a living room). When the third condition (condition
3) corresponds to a case in which human motion is sensed at the
door stop and an intensity of illumination at the front door is
very low (very dark), the third control may turn on all the pre-set
lamps.
[0339] Unlike the foregoing cases, besides the operation of turning
lamps on or off, the first, second, and third controls may be
variously applied according to pre-set operations. For example, the
first, second, and third controls may be associated with operations
of a lamp and an air-conditioner in summer or may be associated
with operations of a lamp and heating in winter.
[0340] Another example of a lighting system using the foregoing
lighting device will be described with reference to FIGS. 45
through 48.
[0341] FIG. 45 is a block diagram schematically illustrating
constituent elements of a lighting system according to another
exemplary embodiment. A lighting system 10000'' according to the
present embodiment may include a motion sensor unit 11000, an
illumination intensity sensor unit 12000, a lighting unit 13000,
and a control unit 14000.
[0342] The motion sensor unit 11000 senses a motion of an object.
For example, the lighting system may be attached to a movable
object, such as, for example, a container or a vehicle, and the
motion sensor unit 11000 senses motion of the object that moves.
When the motion of the object to which the lighting system is
attached is sensed, the motion sensor unit 11000 outputs a signal
to the control unit 14000 and the lighting system is activated. The
motion sensor unit 11000 may include an accelerometer, a
geomagnetic sensor, or the like.
[0343] The illumination intensity sensor unit 12000, a type of
optical sensor, measures an intensity of illumination of a
surrounding environment. When the motion sensor unit 11000 senses a
motion of the object to which the lighting system is attached, the
illumination intensity sensor unit 12000 is activated according to
a signal output by the control unit 14000. The lighting system
illuminates during night work or in a dark environment to call a
worker or an operator's attention to their surroundings, and allows
a driver to secure visibility at night. Thus, even when a motion of
an object to which the lighting system is attached is sensed, if an
intensity of illumination higher than a predetermined level is
secured (during the day), the lighting system is not required to
illuminate. Also, even in the daytime, if it rains, the intensity
of illumination may be fairly low, so there is a need to inform a
worker or an operator about a movement of a container, and thus,
the lighting unit is required to emit light. Thus, whether to turn
on the lighting unit 13000 is determined according to an
illumination intensity value measured by the illumination intensity
sensor unit 12000.
[0344] The illumination intensity sensor unit 12000 measures an
intensity of illumination of a surrounding environment and outputs
the measurement value to the control unit 14000 as described
hereinafter. Meanwhile, when the illumination intensity value is
equal to or higher than a pre-set value, the lighting unit 13000 is
not required to emit light, so the overall system is
terminated.
[0345] When the illumination intensity value measured by the
illumination intensity sensor unit 12000 is lower than the pre-set
value, the lighting unit 13000 emits light. The worker or the
operator may recognize the light emissions from the lighting unit
1300 to recognize a movement of a container, or the like. As the
lighting unit 13000, the foregoing lighting device may be
employed.
[0346] Also, the lighting unit 13000 may adjust intensity of light
emissions thereof according to the illumination intensity value of
the surrounding environment. When the illumination intensity value
of the surrounding environment is low, the lighting unit 13000 may
increase the intensity of light emissions thereof, and when the
illumination intensity value of the surrounding environment is
relatively high, the lighting unit 13000 may decrease the intensity
of light emissions thereof, thus preventing power wastage.
[0347] The control unit 14000 controls the motion sensor unit 1100,
the illumination intensity sensor unit 12000, and the lighting unit
13000 overall. When the motion sensor unit 11000 senses a motion of
an object to which the lighting system is attached, and outputs a
signal to the control unit 14000, the control unit 14000 outputs an
operation signal to the illumination intensity sensor unit 12000.
The control unit 14000 receives an illumination intensity value
measured by the illumination intensity sensor unit 12000 and
determines whether to turn on (operate) the lighting unit
13000.
[0348] FIG. 46 is a flow chart illustrating a method for
controlling a lighting system. Hereinafter, a method for
controlling a lighting system will be described with reference to
FIG. 46.
[0349] First, a motion of an object to which the lighting system is
attached is sensed and an operation signal is output (S310). For
example, the motion sensor unit 11000 may sense a motion of a
container or a vehicle in which the lighting system is installed,
and when a motion of the container or the vehicle is sensed, the
motion sensor unit 11000 outputs an operation signal. The operation
signal may be a signal for activating overall power. Namely, when a
motion of the container or the vehicle is sensed, the motion sensor
unit 11000 outputs an operation signal to the control unit
14000.
[0350] Next, based on the operation signal, an intensity of
illumination of a surrounding environment is measured and an
illumination intensity value is output (S320). When the operation
signal is applied to the control unit 14000, the control unit 14000
outputs a signal to the illumination intensity sensor unit 12000,
and the illumination intensity sensor unit 12000 then measures an
intensity of illumination of the surrounding environment. The
illumination intensity sensor unit 12000 outputs the measured
illumination intensity value of the surrounding environment to the
control unit 14000. Thereafter, whether to turn on the lighting
unit is determined according to the illumination intensity value
and the lighting unit emits light according to the
determination.
[0351] First, the illumination intensity value is compared with a
pre-set value for a determination. When the illumination intensity
value is input to the control unit 14000, the control unit 14000
compares the received illumination intensity value with a stored
pre-set value and determines whether the former is lower than the
latter. Here, the pre-set value is a value for determining whether
to turn on the lighting device. For example, the pre-set value may
be an illumination intensity value at which a worker or a driver
may have difficulty in recognizing an object with the naked eye or
may make a mistake in a situation, for example, a situation in
which the sun starts to set.
[0352] When the illumination intensity value measured by the
illumination intensity sensor unit 12000 is higher than the pre-set
value, lighting of the lighting unit is not required, so the
control unit 14000 shuts down the overall system.
[0353] Meanwhile, when the illumination intensity value measured by
the illumination intensity sensor unit 12000 is higher than the
pre-set value, lighting of the lighting unit is required, so the
control unit 14000 outputs a signal to the lighting unit 13000 and
the lighting unit 13000 emits light (S340).
[0354] FIG. 47 is a flow chart illustrating a method for
controlling a lighting system according to another exemplary
embodiment. Hereinafter, a method for controlling a lighting system
according to another exemplary embodiment will be described.
However, the same procedure as that of the method for controlling a
lighting system as described above with reference to FIG. 46 will
be omitted.
[0355] As illustrated in FIG. 47, in the case of the method for
controlling a lighting system according to the present embodiment,
an intensity of light emissions of the lighting unit may be
regulated according to an illumination intensity value of a
surrounding environment.
[0356] As described above, the illumination intensity sensor unit
12000 outputs an illumination intensity value to the control unit
14000 (S320). When the illumination intensity value is lower than a
pre-set value (S330), the control unit 14000 determines a range of
the illumination intensity value (S340-1). The control unit 14000
has a range of subdivided illumination intensity value, based on
which the control unit 14000 determines the range of the measured
illumination intensity value.
[0357] Next, when the range of the illumination intensity value is
determined, the control unit 14000 determines an intensity of light
emissions of the lighting unit (S340-2), and accordingly, the
lighting unit 13000 emits light (S340-3). The intensity of light
emissions of the lighting unit may be divided according to the
illumination intensity value, and here, the illumination intensity
value varies according to weather, time, and surrounding
environment, so the intensity of light emissions of the lighting
unit may also be regulated. By regulating the intensity of light
emissions according to the range of the illumination intensity
value, power wastage can be prevented and a worker or an operator's
attention may be drawn to their surroundings.
[0358] FIG. 48 is a flow chart illustrating a method for
controlling a lighting system according to another exemplary
embodiment. Hereinafter, a method for controlling a lighting system
according to another exemplary embodiment will be described.
However, the same procedure as that of the method for controlling a
lighting system as described above with reference to FIGS. 46 and
47 will be omitted.
[0359] The method for controlling a lighting system according to
the present embodiment further includes operation S350 of
determining whether a motion of an object to which the lighting
system is attached is maintained in a state in which the lighting
unit 13000 emits light, and determining whether to maintain light
emissions.
[0360] First, when the lighting unit 13000 starts to emit light,
termination of the light emissions may be determined based on
whether a container or a vehicle to which the lighting system is
installed moves. Here, when a motion of the container is stopped,
it may be determined that an operation thereof has terminated. In
addition, when a vehicle temporarily stops at a crosswalk, light
emissions of the lighting unit may be stopped to prevent
interference with vision of oncoming drivers.
[0361] When the container or the vehicle moves again, the motion
sensor unit 11000 operates and the lighting unit 14000 may start to
emit light.
[0362] Whether to maintain light emissions may be determined based
on whether a motion of an object to which the lighting system is
attached is sensed by the motion sensor unit 11000. When a motion
of the object continuously sensed by the motion sensor unit 11000,
an intensity of illumination is measured again and whether to
maintain light emissions is determined. Meanwhile, when a motion of
the object is not sensed, the system is terminated.
[0363] The lighting apparatus using an LED as described above may
be altered in terms of an optical design thereof according to a
product type, a location, and a purpose. For example, in relation
to the foregoing sensitivity illumination, a technique for
controlling lighting by using a wireless (remote) control technique
utilizing a portable device such as a smartphone, in addition to a
technique of controlling a color, temperature, brightness, and a
hue of illumination (or lighting) may be provided.
[0364] Also, in addition, a visible wireless communications
technology aiming at achieving a unique purpose of an LED light
source and a purpose as a communications unit by adding a
communications function to LED lighting apparatuses and display
devices may be available. This is because, an LED light source
advantageously has a longer lifespan and excellent power
efficiency, implements various colors, supports a high switching
rate for digital communications, and is available for digital
control, in comparison to existing light sources.
[0365] The visible light wireless communications technology is a
wireless communications technology transferring information
wirelessly by using light having a visible light wavelength band
recognizable by humans' eyes. The visible light wireless
communications technology is discriminated from a wired optical
communications technology in the aspect that it uses light having a
visible light wavelength band, and discriminated from a wired
optical communications technology in the aspect that a
communication environment is based on a wireless scheme.
[0366] Also, unlike RF wireless communications, the visible light
wireless communications technology has excellent convenience and
physical security properties in that it can be freely used without
being regulated or permitted in the aspect of frequency usage, is
differentiated in that a user can check a communication link with
his/her eyes, and above all, the visible light wireless
communications technology has features as a fusion technique (or
converging technology) obtaining a unique purpose as a light source
and a communications function.
[0367] As set forth above, according to exemplary embodiments, the
lighting apparatus, capable of increasing the lifespan of a light
source and improving light output by overcoming limited heat
radiation efficiency according to natural convection to
significantly increase heat radiation efficiency, can be
provided.
[0368] In addition, the lighting apparatus having a size that falls
within the ANSI standard, while having enhanced heat dissipation
efficiency, can be provided.
[0369] Various advantages and effects of exemplary embodiments are
not limited to the above descriptions, and will be more easily
understood through the explanation of specific exemplary
embodiments.
[0370] While the present invention has been shown and described in
connection with the embodiments, it will be apparent to those
skilled in the art that modifications and variations can be made
without departing from the spirit and scope of the invention as
defined by the appended claims.
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